/*
 * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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/*
 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
 * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
 *
 *   The original version of this source code and documentation is copyrighted
 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
 * materials are provided under terms of a License Agreement between Taligent
 * and Sun. This technology is protected by multiple US and International
 * patents. This notice and attribution to Taligent may not be removed.
 *   Taligent is a registered trademark of Taligent, Inc.
 *
 */

package java.text;

import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.RoundingMode;
import java.text.spi.NumberFormatProvider;
import java.util.ArrayList;
import java.util.Currency;
import java.util.Locale;
import java.util.ResourceBundle;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import sun.util.locale.provider.LocaleProviderAdapter;
import sun.util.locale.provider.ResourceBundleBasedAdapter;

/**
 * <code>DecimalFormat</code> is a concrete subclass of
 * <code>NumberFormat</code> that formats decimal numbers. It has a variety of
 * features designed to make it possible to parse and format numbers in any
 * locale, including support for Western, Arabic, and Indic digits.  It also
 * supports different kinds of numbers, including integers (123), fixed-point
 * numbers (123.4), scientific notation (1.23E4), percentages (12%), and
 * currency amounts ($123).  All of these can be localized.
 *
 * <p>To obtain a <code>NumberFormat</code> for a specific locale, including the
 * default locale, call one of <code>NumberFormat</code>'s factory methods, such
 * as <code>getInstance()</code>.  In general, do not call the
 * <code>DecimalFormat</code> constructors directly, since the
 * <code>NumberFormat</code> factory methods may return subclasses other than
 * <code>DecimalFormat</code>. If you need to customize the format object, do
 * something like this:
 *
 * <blockquote><pre>
 * NumberFormat f = NumberFormat.getInstance(loc);
 * if (f instanceof DecimalFormat) {
 *     ((DecimalFormat) f).setDecimalSeparatorAlwaysShown(true);
 * }
 * </pre></blockquote>
 *
 * <p>A <code>DecimalFormat</code> comprises a <em>pattern</em> and a set of
 * <em>symbols</em>.  The pattern may be set directly using
 * <code>applyPattern()</code>, or indirectly using the API methods.  The
 * symbols are stored in a <code>DecimalFormatSymbols</code> object.  When using
 * the <code>NumberFormat</code> factory methods, the pattern and symbols are
 * read from localized <code>ResourceBundle</code>s.
 *
 * <h3>Patterns</h3>
 *
 * <code>DecimalFormat</code> patterns have the following syntax:
 * <blockquote><pre>
 * <i>Pattern:</i>
 *         <i>PositivePattern</i>
 *         <i>PositivePattern</i> ; <i>NegativePattern</i>
 * <i>PositivePattern:</i>
 *         <i>Prefix<sub>opt</sub></i> <i>Number</i> <i>Suffix<sub>opt</sub></i>
 * <i>NegativePattern:</i>
 *         <i>Prefix<sub>opt</sub></i> <i>Number</i> <i>Suffix<sub>opt</sub></i>
 * <i>Prefix:</i>
 *         any Unicode characters except &#92;uFFFE, &#92;uFFFF, and special characters
 * <i>Suffix:</i>
 *         any Unicode characters except &#92;uFFFE, &#92;uFFFF, and special characters
 * <i>Number:</i>
 *         <i>Integer</i> <i>Exponent<sub>opt</sub></i>
 *         <i>Integer</i> . <i>Fraction</i> <i>Exponent<sub>opt</sub></i>
 * <i>Integer:</i>
 *         <i>MinimumInteger</i>
 *         #
 *         # <i>Integer</i>
 *         # , <i>Integer</i>
 * <i>MinimumInteger:</i>
 *         0
 *         0 <i>MinimumInteger</i>
 *         0 , <i>MinimumInteger</i>
 * <i>Fraction:</i>
 *         <i>MinimumFraction<sub>opt</sub></i> <i>OptionalFraction<sub>opt</sub></i>
 * <i>MinimumFraction:</i>
 *         0 <i>MinimumFraction<sub>opt</sub></i>
 * <i>OptionalFraction:</i>
 *         # <i>OptionalFraction<sub>opt</sub></i>
 * <i>Exponent:</i>
 *         E <i>MinimumExponent</i>
 * <i>MinimumExponent:</i>
 *         0 <i>MinimumExponent<sub>opt</sub></i>
 * </pre></blockquote>
 *
 * <p>A <code>DecimalFormat</code> pattern contains a positive and negative
 * subpattern, for example, <code>"#,##0.00;(#,##0.00)"</code>.  Each
 * subpattern has a prefix, numeric part, and suffix. The negative subpattern
 * is optional; if absent, then the positive subpattern prefixed with the
 * localized minus sign (<code>'-'</code> in most locales) is used as the
 * negative subpattern. That is, <code>"0.00"</code> alone is equivalent to
 * <code>"0.00;-0.00"</code>.  If there is an explicit negative subpattern, it
 * serves only to specify the negative prefix and suffix; the number of digits,
 * minimal digits, and other characteristics are all the same as the positive
 * pattern. That means that <code>"#,##0.0#;(#)"</code> produces precisely
 * the same behavior as <code>"#,##0.0#;(#,##0.0#)"</code>.
 *
 * <p>The prefixes, suffixes, and various symbols used for infinity, digits,
 * thousands separators, decimal separators, etc. may be set to arbitrary
 * values, and they will appear properly during formatting.  However, care must
 * be taken that the symbols and strings do not conflict, or parsing will be
 * unreliable.  For example, either the positive and negative prefixes or the
 * suffixes must be distinct for <code>DecimalFormat.parse()</code> to be able
 * to distinguish positive from negative values.  (If they are identical, then
 * <code>DecimalFormat</code> will behave as if no negative subpattern was
 * specified.)  Another example is that the decimal separator and thousands
 * separator should be distinct characters, or parsing will be impossible.
 *
 * <p>The grouping separator is commonly used for thousands, but in some
 * countries it separates ten-thousands. The grouping size is a constant number
 * of digits between the grouping characters, such as 3 for 100,000,000 or 4 for
 * 1,0000,0000.  If you supply a pattern with multiple grouping characters, the
 * interval between the last one and the end of the integer is the one that is
 * used. So <code>"#,##,###,####"</code> == <code>"######,####"</code> ==
 * <code>"##,####,####"</code>.
 *
 * <h4>Special Pattern Characters</h4>
 *
 * <p>Many characters in a pattern are taken literally; they are matched during
 * parsing and output unchanged during formatting.  Special characters, on the
 * other hand, stand for other characters, strings, or classes of characters.
 * They must be quoted, unless noted otherwise, if they are to appear in the
 * prefix or suffix as literals.
 *
 * <p>The characters listed here are used in non-localized patterns.  Localized
 * patterns use the corresponding characters taken from this formatter's
 * <code>DecimalFormatSymbols</code> object instead, and these characters lose
 * their special status.  Two exceptions are the currency sign and quote, which
 * are not localized.
 *
 * <blockquote>
 * <table border=0 cellspacing=3 cellpadding=0 summary="Chart showing symbol,
 * location, localized, and meaning.">
 * <tr style="background-color: rgb(204, 204, 255);">
 * <th align=left>Symbol
 * <th align=left>Location
 * <th align=left>Localized?
 * <th align=left>Meaning
 * <tr valign=top>
 * <td><code>0</code>
 * <td>Number
 * <td>Yes
 * <td>Digit
 * <tr style="vertical-align: top; background-color: rgb(238, 238, 255);">
 * <td><code>#</code>
 * <td>Number
 * <td>Yes
 * <td>Digit, zero shows as absent
 * <tr valign=top>
 * <td><code>.</code>
 * <td>Number
 * <td>Yes
 * <td>Decimal separator or monetary decimal separator
 * <tr style="vertical-align: top; background-color: rgb(238, 238, 255);">
 * <td><code>-</code>
 * <td>Number
 * <td>Yes
 * <td>Minus sign
 * <tr valign=top>
 * <td><code>,</code>
 * <td>Number
 * <td>Yes
 * <td>Grouping separator
 * <tr style="vertical-align: top; background-color: rgb(238, 238, 255);">
 * <td><code>E</code>
 * <td>Number
 * <td>Yes
 * <td>Separates mantissa and exponent in scientific notation.
 * <em>Need not be quoted in prefix or suffix.</em>
 * <tr valign=top>
 * <td><code>;</code>
 * <td>Subpattern boundary
 * <td>Yes
 * <td>Separates positive and negative subpatterns
 * <tr style="vertical-align: top; background-color: rgb(238, 238, 255);">
 * <td><code>%</code>
 * <td>Prefix or suffix
 * <td>Yes
 * <td>Multiply by 100 and show as percentage
 * <tr valign=top>
 * <td><code>&#92;u2030</code>
 * <td>Prefix or suffix
 * <td>Yes
 * <td>Multiply by 1000 and show as per mille value
 * <tr style="vertical-align: top; background-color: rgb(238, 238, 255);">
 * <td><code>&#164;</code> (<code>&#92;u00A4</code>)
 * <td>Prefix or suffix
 * <td>No
 * <td>Currency sign, replaced by currency symbol.  If
 * doubled, replaced by international currency symbol.
 * If present in a pattern, the monetary decimal separator
 * is used instead of the decimal separator.
 * <tr valign=top>
 * <td><code>'</code>
 * <td>Prefix or suffix
 * <td>No
 * <td>Used to quote special characters in a prefix or suffix,
 * for example, <code>"'#'#"</code> formats 123 to
 * <code>"#123"</code>.  To create a single quote
 * itself, use two in a row: <code>"# o''clock"</code>.
 * </table>
 * </blockquote>
 *
 * <h4>Scientific Notation</h4>
 *
 * <p>Numbers in scientific notation are expressed as the product of a mantissa
 * and a power of ten, for example, 1234 can be expressed as 1.234 x 10^3.  The
 * mantissa is often in the range 1.0 &le; x {@literal <} 10.0, but it need not
 * be.
 * <code>DecimalFormat</code> can be instructed to format and parse scientific
 * notation <em>only via a pattern</em>; there is currently no factory method
 * that creates a scientific notation format.  In a pattern, the exponent
 * character immediately followed by one or more digit characters indicates
 * scientific notation.  Example: <code>"0.###E0"</code> formats the number
 * 1234 as <code>"1.234E3"</code>.
 *
 * <ul>
 * <li>The number of digit characters after the exponent character gives the
 * minimum exponent digit count.  There is no maximum.  Negative exponents are
 * formatted using the localized minus sign, <em>not</em> the prefix and suffix
 * from the pattern.  This allows patterns such as <code>"0.###E0 m/s"</code>.
 *
 * <li>The minimum and maximum number of integer digits are interpreted
 * together:
 *
 * <ul>
 * <li>If the maximum number of integer digits is greater than their minimum number
 * and greater than 1, it forces the exponent to be a multiple of the maximum
 * number of integer digits, and the minimum number of integer digits to be
 * interpreted as 1.  The most common use of this is to generate
 * <em>engineering notation</em>, in which the exponent is a multiple of three,
 * e.g., <code>"##0.#####E0"</code>. Using this pattern, the number 12345
 * formats to <code>"12.345E3"</code>, and 123456 formats to
 * <code>"123.456E3"</code>.
 *
 * <li>Otherwise, the minimum number of integer digits is achieved by adjusting the
 * exponent.  Example: 0.00123 formatted with <code>"00.###E0"</code> yields
 * <code>"12.3E-4"</code>.
 * </ul>
 *
 * <li>The number of significant digits in the mantissa is the sum of the
 * <em>minimum integer</em> and <em>maximum fraction</em> digits, and is
 * unaffected by the maximum integer digits.  For example, 12345 formatted with
 * <code>"##0.##E0"</code> is <code>"12.3E3"</code>. To show all digits, set
 * the significant digits count to zero.  The number of significant digits
 * does not affect parsing.
 *
 * <li>Exponential patterns may not contain grouping separators.
 * </ul>
 *
 * <h4>Rounding</h4>
 *
 * <code>DecimalFormat</code> provides rounding modes defined in
 * {@link java.math.RoundingMode} for formatting.  By default, it uses
 * {@link java.math.RoundingMode#HALF_EVEN RoundingMode.HALF_EVEN}.
 *
 * <h4>Digits</h4>
 *
 * For formatting, <code>DecimalFormat</code> uses the ten consecutive
 * characters starting with the localized zero digit defined in the
 * <code>DecimalFormatSymbols</code> object as digits. For parsing, these
 * digits as well as all Unicode decimal digits, as defined by
 * {@link Character#digit Character.digit}, are recognized.
 *
 * <h4>Special Values</h4>
 *
 * <p><code>NaN</code> is formatted as a string, which typically has a single character
 * <code>&#92;uFFFD</code>.  This string is determined by the
 * <code>DecimalFormatSymbols</code> object.  This is the only value for which
 * the prefixes and suffixes are not used.
 *
 * <p>Infinity is formatted as a string, which typically has a single character
 * <code>&#92;u221E</code>, with the positive or negative prefixes and suffixes
 * applied.  The infinity string is determined by the
 * <code>DecimalFormatSymbols</code> object.
 *
 * <p>Negative zero (<code>"-0"</code>) parses to
 * <ul>
 * <li><code>BigDecimal(0)</code> if <code>isParseBigDecimal()</code> is
 * true,
 * <li><code>Long(0)</code> if <code>isParseBigDecimal()</code> is false
 * and <code>isParseIntegerOnly()</code> is true,
 * <li><code>Double(-0.0)</code> if both <code>isParseBigDecimal()</code>
 * and <code>isParseIntegerOnly()</code> are false.
 * </ul>
 *
 * <h4><a name="synchronization">Synchronization</a></h4>
 *
 * <p>
 * Decimal formats are generally not synchronized.
 * It is recommended to create separate format instances for each thread.
 * If multiple threads access a format concurrently, it must be synchronized
 * externally.
 *
 * <h4>Example</h4>
 *
 * <blockquote><pre>{@code
 * <strong>// Print out a number using the localized number, integer, currency,
 * // and percent format for each locale</strong>
 * Locale[] locales = NumberFormat.getAvailableLocales();
 * double myNumber = -1234.56;
 * NumberFormat form;
 * for (int j = 0; j < 4; ++j) {
 *     System.out.println("FORMAT");
 *     for (int i = 0; i < locales.length; ++i) {
 *         if (locales[i].getCountry().length() == 0) {
 *            continue; // Skip language-only locales
 *         }
 *         System.out.print(locales[i].getDisplayName());
 *         switch (j) {
 *         case 0:
 *             form = NumberFormat.getInstance(locales[i]); break;
 *         case 1:
 *             form = NumberFormat.getIntegerInstance(locales[i]); break;
 *         case 2:
 *             form = NumberFormat.getCurrencyInstance(locales[i]); break;
 *         default:
 *             form = NumberFormat.getPercentInstance(locales[i]); break;
 *         }
 *         if (form instanceof DecimalFormat) {
 *             System.out.print(": " + ((DecimalFormat) form).toPattern());
 *         }
 *         System.out.print(" -> " + form.format(myNumber));
 *         try {
 *             System.out.println(" -> " + form.parse(form.format(myNumber)));
 *         } catch (ParseException e) {}
 *     }
 * }
 * }</pre></blockquote>
 *
 * @author Mark Davis
 * @author Alan Liu
 * @see <a href="https://docs.oracle.com/javase/tutorial/i18n/format/decimalFormat.html">Java
 * Tutorial</a>
 * @see NumberFormat
 * @see DecimalFormatSymbols
 * @see ParsePosition
 */
public class DecimalFormat extends NumberFormat {

  /**
   * Creates a DecimalFormat using the default pattern and symbols
   * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
   * This is a convenient way to obtain a
   * DecimalFormat when internationalization is not the main concern.
   * <p>
   * To obtain standard formats for a given locale, use the factory methods
   * on NumberFormat such as getNumberInstance. These factories will
   * return the most appropriate sub-class of NumberFormat for a given
   * locale.
   *
   * @see java.text.NumberFormat#getInstance
   * @see java.text.NumberFormat#getNumberInstance
   * @see java.text.NumberFormat#getCurrencyInstance
   * @see java.text.NumberFormat#getPercentInstance
   */
  public DecimalFormat() {
    // Get the pattern for the default locale.
    Locale def = Locale.getDefault(Locale.Category.FORMAT);
    LocaleProviderAdapter adapter = LocaleProviderAdapter
        .getAdapter(NumberFormatProvider.class, def);
    if (!(adapter instanceof ResourceBundleBasedAdapter)) {
      adapter = LocaleProviderAdapter.getResourceBundleBased();
    }
    String[] all = adapter.getLocaleResources(def).getNumberPatterns();

    // Always applyPattern after the symbols are set
    this.symbols = DecimalFormatSymbols.getInstance(def);
    applyPattern(all[0], false);
  }


  /**
   * Creates a DecimalFormat using the given pattern and the symbols
   * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
   * This is a convenient way to obtain a
   * DecimalFormat when internationalization is not the main concern.
   * <p>
   * To obtain standard formats for a given locale, use the factory methods
   * on NumberFormat such as getNumberInstance. These factories will
   * return the most appropriate sub-class of NumberFormat for a given
   * locale.
   *
   * @param pattern a non-localized pattern string.
   * @throws NullPointerException if <code>pattern</code> is null
   * @throws IllegalArgumentException if the given pattern is invalid.
   * @see java.text.NumberFormat#getInstance
   * @see java.text.NumberFormat#getNumberInstance
   * @see java.text.NumberFormat#getCurrencyInstance
   * @see java.text.NumberFormat#getPercentInstance
   */
  public DecimalFormat(String pattern) {
    // Always applyPattern after the symbols are set
    this.symbols = DecimalFormatSymbols.getInstance(Locale.getDefault(Locale.Category.FORMAT));
    applyPattern(pattern, false);
  }


  /**
   * Creates a DecimalFormat using the given pattern and symbols.
   * Use this constructor when you need to completely customize the
   * behavior of the format.
   * <p>
   * To obtain standard formats for a given
   * locale, use the factory methods on NumberFormat such as
   * getInstance or getCurrencyInstance. If you need only minor adjustments
   * to a standard format, you can modify the format returned by
   * a NumberFormat factory method.
   *
   * @param pattern a non-localized pattern string
   * @param symbols the set of symbols to be used
   * @throws NullPointerException if any of the given arguments is null
   * @throws IllegalArgumentException if the given pattern is invalid
   * @see java.text.NumberFormat#getInstance
   * @see java.text.NumberFormat#getNumberInstance
   * @see java.text.NumberFormat#getCurrencyInstance
   * @see java.text.NumberFormat#getPercentInstance
   * @see java.text.DecimalFormatSymbols
   */
  public DecimalFormat(String pattern, DecimalFormatSymbols symbols) {
    // Always applyPattern after the symbols are set
    this.symbols = (DecimalFormatSymbols) symbols.clone();
    applyPattern(pattern, false);
  }

  // Overrides

  /**
   * Formats a number and appends the resulting text to the given string
   * buffer.
   * The number can be of any subclass of {@link java.lang.Number}.
   * <p>
   * This implementation uses the maximum precision permitted.
   *
   * @param number the number to format
   * @param toAppendTo the <code>StringBuffer</code> to which the formatted text is to be appended
   * @param pos On input: an alignment field, if desired. On output: the offsets of the alignment
   * field.
   * @return the value passed in as <code>toAppendTo</code>
   * @throws IllegalArgumentException if <code>number</code> is null or not an instance of
   * <code>Number</code>.
   * @throws NullPointerException if <code>toAppendTo</code> or <code>pos</code> is null
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   * @see java.text.FieldPosition
   */
  @Override
  public final StringBuffer format(Object number,
      StringBuffer toAppendTo,
      FieldPosition pos) {
    if (number instanceof Long || number instanceof Integer ||
        number instanceof Short || number instanceof Byte ||
        number instanceof AtomicInteger ||
        number instanceof AtomicLong ||
        (number instanceof BigInteger &&
            ((BigInteger) number).bitLength() < 64)) {
      return format(((Number) number).longValue(), toAppendTo, pos);
    } else if (number instanceof BigDecimal) {
      return format((BigDecimal) number, toAppendTo, pos);
    } else if (number instanceof BigInteger) {
      return format((BigInteger) number, toAppendTo, pos);
    } else if (number instanceof Number) {
      return format(((Number) number).doubleValue(), toAppendTo, pos);
    } else {
      throw new IllegalArgumentException("Cannot format given Object as a Number");
    }
  }

  /**
   * Formats a double to produce a string.
   *
   * @param number The double to format
   * @param result where the text is to be appended
   * @param fieldPosition On input: an alignment field, if desired. On output: the offsets of the
   * alignment field.
   * @return The formatted number string
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   * @see java.text.FieldPosition
   */
  @Override
  public StringBuffer format(double number, StringBuffer result,
      FieldPosition fieldPosition) {
    // If fieldPosition is a DontCareFieldPosition instance we can
    // try to go to fast-path code.
    boolean tryFastPath = false;
    if (fieldPosition == DontCareFieldPosition.INSTANCE) {
      tryFastPath = true;
    } else {
      fieldPosition.setBeginIndex(0);
      fieldPosition.setEndIndex(0);
    }

    if (tryFastPath) {
      String tempResult = fastFormat(number);
      if (tempResult != null) {
        result.append(tempResult);
        return result;
      }
    }

    // if fast-path could not work, we fallback to standard code.
    return format(number, result, fieldPosition.getFieldDelegate());
  }

  /**
   * Formats a double to produce a string.
   *
   * @param number The double to format
   * @param result where the text is to be appended
   * @param delegate notified of locations of sub fields
   * @return The formatted number string
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   */
  private StringBuffer format(double number, StringBuffer result,
      FieldDelegate delegate) {
    if (Double.isNaN(number) ||
        (Double.isInfinite(number) && multiplier == 0)) {
      int iFieldStart = result.length();
      result.append(symbols.getNaN());
      delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
          iFieldStart, result.length(), result);
      return result;
    }

        /* Detecting whether a double is negative is easy with the exception of
         * the value -0.0.  This is a double which has a zero mantissa (and
         * exponent), but a negative sign bit.  It is semantically distinct from
         * a zero with a positive sign bit, and this distinction is important
         * to certain kinds of computations.  However, it's a little tricky to
         * detect, since (-0.0 == 0.0) and !(-0.0 < 0.0).  How then, you may
         * ask, does it behave distinctly from +0.0?  Well, 1/(-0.0) ==
         * -Infinity.  Proper detection of -0.0 is needed to deal with the
         * issues raised by bugs 4106658, 4106667, and 4147706.  Liu 7/6/98.
         */
    boolean isNegative = ((number < 0.0) || (number == 0.0 && 1 / number < 0.0)) ^ (multiplier < 0);

    if (multiplier != 1) {
      number *= multiplier;
    }

    if (Double.isInfinite(number)) {
      if (isNegative) {
        append(result, negativePrefix, delegate,
            getNegativePrefixFieldPositions(), Field.SIGN);
      } else {
        append(result, positivePrefix, delegate,
            getPositivePrefixFieldPositions(), Field.SIGN);
      }

      int iFieldStart = result.length();
      result.append(symbols.getInfinity());
      delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
          iFieldStart, result.length(), result);

      if (isNegative) {
        append(result, negativeSuffix, delegate,
            getNegativeSuffixFieldPositions(), Field.SIGN);
      } else {
        append(result, positiveSuffix, delegate,
            getPositiveSuffixFieldPositions(), Field.SIGN);
      }

      return result;
    }

    if (isNegative) {
      number = -number;
    }

    // at this point we are guaranteed a nonnegative finite number.
    assert (number >= 0 && !Double.isInfinite(number));

    synchronized (digitList) {
      int maxIntDigits = super.getMaximumIntegerDigits();
      int minIntDigits = super.getMinimumIntegerDigits();
      int maxFraDigits = super.getMaximumFractionDigits();
      int minFraDigits = super.getMinimumFractionDigits();

      digitList.set(isNegative, number, useExponentialNotation ?
              maxIntDigits + maxFraDigits : maxFraDigits,
          !useExponentialNotation);
      return subformat(result, delegate, isNegative, false,
          maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
    }
  }

  /**
   * Format a long to produce a string.
   *
   * @param number The long to format
   * @param result where the text is to be appended
   * @param fieldPosition On input: an alignment field, if desired. On output: the offsets of the
   * alignment field.
   * @return The formatted number string
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   * @see java.text.FieldPosition
   */
  @Override
  public StringBuffer format(long number, StringBuffer result,
      FieldPosition fieldPosition) {
    fieldPosition.setBeginIndex(0);
    fieldPosition.setEndIndex(0);

    return format(number, result, fieldPosition.getFieldDelegate());
  }

  /**
   * Format a long to produce a string.
   *
   * @param number The long to format
   * @param result where the text is to be appended
   * @param delegate notified of locations of sub fields
   * @return The formatted number string
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   * @see java.text.FieldPosition
   */
  private StringBuffer format(long number, StringBuffer result,
      FieldDelegate delegate) {
    boolean isNegative = (number < 0);
    if (isNegative) {
      number = -number;
    }

    // In general, long values always represent real finite numbers, so
    // we don't have to check for +/- Infinity or NaN.  However, there
    // is one case we have to be careful of:  The multiplier can push
    // a number near MIN_VALUE or MAX_VALUE outside the legal range.  We
    // check for this before multiplying, and if it happens we use
    // BigInteger instead.
    boolean useBigInteger = false;
    if (number < 0) { // This can only happen if number == Long.MIN_VALUE.
      if (multiplier != 0) {
        useBigInteger = true;
      }
    } else if (multiplier != 1 && multiplier != 0) {
      long cutoff = Long.MAX_VALUE / multiplier;
      if (cutoff < 0) {
        cutoff = -cutoff;
      }
      useBigInteger = (number > cutoff);
    }

    if (useBigInteger) {
      if (isNegative) {
        number = -number;
      }
      BigInteger bigIntegerValue = BigInteger.valueOf(number);
      return format(bigIntegerValue, result, delegate, true);
    }

    number *= multiplier;
    if (number == 0) {
      isNegative = false;
    } else {
      if (multiplier < 0) {
        number = -number;
        isNegative = !isNegative;
      }
    }

    synchronized (digitList) {
      int maxIntDigits = super.getMaximumIntegerDigits();
      int minIntDigits = super.getMinimumIntegerDigits();
      int maxFraDigits = super.getMaximumFractionDigits();
      int minFraDigits = super.getMinimumFractionDigits();

      digitList.set(isNegative, number,
          useExponentialNotation ? maxIntDigits + maxFraDigits : 0);

      return subformat(result, delegate, isNegative, true,
          maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
    }
  }

  /**
   * Formats a BigDecimal to produce a string.
   *
   * @param number The BigDecimal to format
   * @param result where the text is to be appended
   * @param fieldPosition On input: an alignment field, if desired. On output: the offsets of the
   * alignment field.
   * @return The formatted number string
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   * @see java.text.FieldPosition
   */
  private StringBuffer format(BigDecimal number, StringBuffer result,
      FieldPosition fieldPosition) {
    fieldPosition.setBeginIndex(0);
    fieldPosition.setEndIndex(0);
    return format(number, result, fieldPosition.getFieldDelegate());
  }

  /**
   * Formats a BigDecimal to produce a string.
   *
   * @param number The BigDecimal to format
   * @param result where the text is to be appended
   * @param delegate notified of locations of sub fields
   * @return The formatted number string
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   */
  private StringBuffer format(BigDecimal number, StringBuffer result,
      FieldDelegate delegate) {
    if (multiplier != 1) {
      number = number.multiply(getBigDecimalMultiplier());
    }
    boolean isNegative = number.signum() == -1;
    if (isNegative) {
      number = number.negate();
    }

    synchronized (digitList) {
      int maxIntDigits = getMaximumIntegerDigits();
      int minIntDigits = getMinimumIntegerDigits();
      int maxFraDigits = getMaximumFractionDigits();
      int minFraDigits = getMinimumFractionDigits();
      int maximumDigits = maxIntDigits + maxFraDigits;

      digitList.set(isNegative, number, useExponentialNotation ?
          ((maximumDigits < 0) ? Integer.MAX_VALUE : maximumDigits) :
          maxFraDigits, !useExponentialNotation);

      return subformat(result, delegate, isNegative, false,
          maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
    }
  }

  /**
   * Format a BigInteger to produce a string.
   *
   * @param number The BigInteger to format
   * @param result where the text is to be appended
   * @param fieldPosition On input: an alignment field, if desired. On output: the offsets of the
   * alignment field.
   * @return The formatted number string
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   * @see java.text.FieldPosition
   */
  private StringBuffer format(BigInteger number, StringBuffer result,
      FieldPosition fieldPosition) {
    fieldPosition.setBeginIndex(0);
    fieldPosition.setEndIndex(0);

    return format(number, result, fieldPosition.getFieldDelegate(), false);
  }

  /**
   * Format a BigInteger to produce a string.
   *
   * @param number The BigInteger to format
   * @param result where the text is to be appended
   * @param delegate notified of locations of sub fields
   * @return The formatted number string
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   * @see java.text.FieldPosition
   */
  private StringBuffer format(BigInteger number, StringBuffer result,
      FieldDelegate delegate, boolean formatLong) {
    if (multiplier != 1) {
      number = number.multiply(getBigIntegerMultiplier());
    }
    boolean isNegative = number.signum() == -1;
    if (isNegative) {
      number = number.negate();
    }

    synchronized (digitList) {
      int maxIntDigits, minIntDigits, maxFraDigits, minFraDigits, maximumDigits;
      if (formatLong) {
        maxIntDigits = super.getMaximumIntegerDigits();
        minIntDigits = super.getMinimumIntegerDigits();
        maxFraDigits = super.getMaximumFractionDigits();
        minFraDigits = super.getMinimumFractionDigits();
        maximumDigits = maxIntDigits + maxFraDigits;
      } else {
        maxIntDigits = getMaximumIntegerDigits();
        minIntDigits = getMinimumIntegerDigits();
        maxFraDigits = getMaximumFractionDigits();
        minFraDigits = getMinimumFractionDigits();
        maximumDigits = maxIntDigits + maxFraDigits;
        if (maximumDigits < 0) {
          maximumDigits = Integer.MAX_VALUE;
        }
      }

      digitList.set(isNegative, number,
          useExponentialNotation ? maximumDigits : 0);

      return subformat(result, delegate, isNegative, true,
          maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
    }
  }

  /**
   * Formats an Object producing an <code>AttributedCharacterIterator</code>.
   * You can use the returned <code>AttributedCharacterIterator</code>
   * to build the resulting String, as well as to determine information
   * about the resulting String.
   * <p>
   * Each attribute key of the AttributedCharacterIterator will be of type
   * <code>NumberFormat.Field</code>, with the attribute value being the
   * same as the attribute key.
   *
   * @param obj The object to format
   * @return AttributedCharacterIterator describing the formatted value.
   * @throws NullPointerException if obj is null.
   * @throws IllegalArgumentException when the Format cannot format the given object.
   * @throws ArithmeticException if rounding is needed with rounding mode being set to
   * RoundingMode.UNNECESSARY
   * @since 1.4
   */
  @Override
  public AttributedCharacterIterator formatToCharacterIterator(Object obj) {
    CharacterIteratorFieldDelegate delegate =
        new CharacterIteratorFieldDelegate();
    StringBuffer sb = new StringBuffer();

    if (obj instanceof Double || obj instanceof Float) {
      format(((Number) obj).doubleValue(), sb, delegate);
    } else if (obj instanceof Long || obj instanceof Integer ||
        obj instanceof Short || obj instanceof Byte ||
        obj instanceof AtomicInteger || obj instanceof AtomicLong) {
      format(((Number) obj).longValue(), sb, delegate);
    } else if (obj instanceof BigDecimal) {
      format((BigDecimal) obj, sb, delegate);
    } else if (obj instanceof BigInteger) {
      format((BigInteger) obj, sb, delegate, false);
    } else if (obj == null) {
      throw new NullPointerException(
          "formatToCharacterIterator must be passed non-null object");
    } else {
      throw new IllegalArgumentException(
          "Cannot format given Object as a Number");
    }
    return delegate.getIterator(sb.toString());
  }

  // ==== Begin fast-path formating logic for double =========================

    /* Fast-path formatting will be used for format(double ...) methods iff a
     * number of conditions are met (see checkAndSetFastPathStatus()):
     * - Only if instance properties meet the right predefined conditions.
     * - The abs value of the double to format is <= Integer.MAX_VALUE.
     *
     * The basic approach is to split the binary to decimal conversion of a
     * double value into two phases:
     * * The conversion of the integer portion of the double.
     * * The conversion of the fractional portion of the double
     *   (limited to two or three digits).
     *
     * The isolation and conversion of the integer portion of the double is
     * straightforward. The conversion of the fraction is more subtle and relies
     * on some rounding properties of double to the decimal precisions in
     * question.  Using the terminology of BigDecimal, this fast-path algorithm
     * is applied when a double value has a magnitude less than Integer.MAX_VALUE
     * and rounding is to nearest even and the destination format has two or
     * three digits of *scale* (digits after the decimal point).
     *
     * Under a rounding to nearest even policy, the returned result is a digit
     * string of a number in the (in this case decimal) destination format
     * closest to the exact numerical value of the (in this case binary) input
     * value.  If two destination format numbers are equally distant, the one
     * with the last digit even is returned.  To compute such a correctly rounded
     * value, some information about digits beyond the smallest returned digit
     * position needs to be consulted.
     *
     * In general, a guard digit, a round digit, and a sticky *bit* are needed
     * beyond the returned digit position.  If the discarded portion of the input
     * is sufficiently large, the returned digit string is incremented.  In round
     * to nearest even, this threshold to increment occurs near the half-way
     * point between digits.  The sticky bit records if there are any remaining
     * trailing digits of the exact input value in the new format; the sticky bit
     * is consulted only in close to half-way rounding cases.
     *
     * Given the computation of the digit and bit values, rounding is then
     * reduced to a table lookup problem.  For decimal, the even/odd cases look
     * like this:
     *
     * Last   Round   Sticky
     * 6      5       0      => 6   // exactly halfway, return even digit.
     * 6      5       1      => 7   // a little bit more than halfway, round up.
     * 7      5       0      => 8   // exactly halfway, round up to even.
     * 7      5       1      => 8   // a little bit more than halfway, round up.
     * With analogous entries for other even and odd last-returned digits.
     *
     * However, decimal negative powers of 5 smaller than 0.5 are *not* exactly
     * representable as binary fraction.  In particular, 0.005 (the round limit
     * for a two-digit scale) and 0.0005 (the round limit for a three-digit
     * scale) are not representable. Therefore, for input values near these cases
     * the sticky bit is known to be set which reduces the rounding logic to:
     *
     * Last   Round   Sticky
     * 6      5       1      => 7   // a little bit more than halfway, round up.
     * 7      5       1      => 8   // a little bit more than halfway, round up.
     *
     * In other words, if the round digit is 5, the sticky bit is known to be
     * set.  If the round digit is something other than 5, the sticky bit is not
     * relevant.  Therefore, some of the logic about whether or not to increment
     * the destination *decimal* value can occur based on tests of *binary*
     * computations of the binary input number.
     */

  /**
   * Check validity of using fast-path for this instance. If fast-path is valid
   * for this instance, sets fast-path state as true and initializes fast-path
   * utility fields as needed.
   *
   * This method is supposed to be called rarely, otherwise that will break the
   * fast-path performance. That means avoiding frequent changes of the
   * properties of the instance, since for most properties, each time a change
   * happens, a call to this method is needed at the next format call.
   *
   * FAST-PATH RULES:
   * Similar to the default DecimalFormat instantiation case.
   * More precisely:
   * - HALF_EVEN rounding mode,
   * - isGroupingUsed() is true,
   * - groupingSize of 3,
   * - multiplier is 1,
   * - Decimal separator not mandatory,
   * - No use of exponential notation,
   * - minimumIntegerDigits is exactly 1 and maximumIntegerDigits at least 10
   * - For number of fractional digits, the exact values found in the default case:
   * Currency : min = max = 2.
   * Decimal  : min = 0. max = 3.
   */
  private void checkAndSetFastPathStatus() {

    boolean fastPathWasOn = isFastPath;

    if ((roundingMode == RoundingMode.HALF_EVEN) &&
        (isGroupingUsed()) &&
        (groupingSize == 3) &&
        (multiplier == 1) &&
        (!decimalSeparatorAlwaysShown) &&
        (!useExponentialNotation)) {

      // The fast-path algorithm is semi-hardcoded against
      //  minimumIntegerDigits and maximumIntegerDigits.
      isFastPath = ((minimumIntegerDigits == 1) &&
          (maximumIntegerDigits >= 10));

      // The fast-path algorithm is hardcoded against
      //  minimumFractionDigits and maximumFractionDigits.
      if (isFastPath) {
        if (isCurrencyFormat) {
          if ((minimumFractionDigits != 2) ||
              (maximumFractionDigits != 2)) {
            isFastPath = false;
          }
        } else if ((minimumFractionDigits != 0) ||
            (maximumFractionDigits != 3)) {
          isFastPath = false;
        }
      }
    } else {
      isFastPath = false;
    }

    // Since some instance properties may have changed while still falling
    // in the fast-path case, we need to reinitialize fastPathData anyway.
    if (isFastPath) {
      // We need to instantiate fastPathData if not already done.
      if (fastPathData == null) {
        fastPathData = new FastPathData();
      }

      // Sets up the locale specific constants used when formatting.
      // '0' is our default representation of zero.
      fastPathData.zeroDelta = symbols.getZeroDigit() - '0';
      fastPathData.groupingChar = symbols.getGroupingSeparator();

      // Sets up fractional constants related to currency/decimal pattern.
      fastPathData.fractionalMaxIntBound = (isCurrencyFormat) ? 99 : 999;
      fastPathData.fractionalScaleFactor = (isCurrencyFormat) ? 100.0d : 1000.0d;

      // Records the need for adding prefix or suffix
      fastPathData.positiveAffixesRequired =
          (positivePrefix.length() != 0) || (positiveSuffix.length() != 0);
      fastPathData.negativeAffixesRequired =
          (negativePrefix.length() != 0) || (negativeSuffix.length() != 0);

      // Creates a cached char container for result, with max possible size.
      int maxNbIntegralDigits = 10;
      int maxNbGroups = 3;
      int containerSize =
          Math.max(positivePrefix.length(), negativePrefix.length()) +
              maxNbIntegralDigits + maxNbGroups + 1 + maximumFractionDigits +
              Math.max(positiveSuffix.length(), negativeSuffix.length());

      fastPathData.fastPathContainer = new char[containerSize];

      // Sets up prefix and suffix char arrays constants.
      fastPathData.charsPositiveSuffix = positiveSuffix.toCharArray();
      fastPathData.charsNegativeSuffix = negativeSuffix.toCharArray();
      fastPathData.charsPositivePrefix = positivePrefix.toCharArray();
      fastPathData.charsNegativePrefix = negativePrefix.toCharArray();

      // Sets up fixed index positions for integral and fractional digits.
      // Sets up decimal point in cached result container.
      int longestPrefixLength =
          Math.max(positivePrefix.length(), negativePrefix.length());
      int decimalPointIndex =
          maxNbIntegralDigits + maxNbGroups + longestPrefixLength;

      fastPathData.integralLastIndex = decimalPointIndex - 1;
      fastPathData.fractionalFirstIndex = decimalPointIndex + 1;
      fastPathData.fastPathContainer[decimalPointIndex] =
          isCurrencyFormat ?
              symbols.getMonetaryDecimalSeparator() :
              symbols.getDecimalSeparator();

    } else if (fastPathWasOn) {
      // Previous state was fast-path and is no more.
      // Resets cached array constants.
      fastPathData.fastPathContainer = null;
      fastPathData.charsPositiveSuffix = null;
      fastPathData.charsNegativeSuffix = null;
      fastPathData.charsPositivePrefix = null;
      fastPathData.charsNegativePrefix = null;
    }

    fastPathCheckNeeded = false;
  }

  /**
   * Returns true if rounding-up must be done on {@code scaledFractionalPartAsInt},
   * false otherwise.
   *
   * This is a utility method that takes correct half-even rounding decision on
   * passed fractional value at the scaled decimal point (2 digits for currency
   * case and 3 for decimal case), when the approximated fractional part after
   * scaled decimal point is exactly 0.5d.  This is done by means of exact
   * calculations on the {@code fractionalPart} floating-point value.
   *
   * This method is supposed to be called by private {@code fastDoubleFormat}
   * method only.
   *
   * The algorithms used for the exact calculations are :
   *
   * The <b><i>FastTwoSum</i></b> algorithm, from T.J.Dekker, described in the
   * papers  "<i>A  Floating-Point   Technique  for  Extending  the  Available
   * Precision</i>"  by Dekker, and  in "<i>Adaptive  Precision Floating-Point
   * Arithmetic and Fast Robust Geometric Predicates</i>" from J.Shewchuk.
   *
   * A modified version of <b><i>Sum2S</i></b> cascaded summation described in
   * "<i>Accurate Sum and Dot Product</i>" from Takeshi Ogita and All.  As
   * Ogita says in this paper this is an equivalent of the Kahan-Babuska's
   * summation algorithm because we order the terms by magnitude before summing
   * them. For this reason we can use the <i>FastTwoSum</i> algorithm rather
   * than the more expensive Knuth's <i>TwoSum</i>.
   *
   * We do this to avoid a more expensive exact "<i>TwoProduct</i>" algorithm,
   * like those described in Shewchuk's paper above. See comments in the code
   * below.
   *
   * @param fractionalPart The  fractional value  on which  we  take rounding decision.
   * @param scaledFractionalPartAsInt The integral part of the scaled fractional value.
   * @return the decision that must be taken regarding half-even rounding.
   */
  private boolean exactRoundUp(double fractionalPart,
      int scaledFractionalPartAsInt) {

        /* exactRoundUp() method is called by fastDoubleFormat() only.
         * The precondition expected to be verified by the passed parameters is :
         * scaledFractionalPartAsInt ==
         *     (int) (fractionalPart * fastPathData.fractionalScaleFactor).
         * This is ensured by fastDoubleFormat() code.
         */

        /* We first calculate roundoff error made by fastDoubleFormat() on
         * the scaled fractional part. We do this with exact calculation on the
         * passed fractionalPart. Rounding decision will then be taken from roundoff.
         */

        /* ---- TwoProduct(fractionalPart, scale factor (i.e. 1000.0d or 100.0d)).
         *
         * The below is an optimized exact "TwoProduct" calculation of passed
         * fractional part with scale factor, using Ogita's Sum2S cascaded
         * summation adapted as Kahan-Babuska equivalent by using FastTwoSum
         * (much faster) rather than Knuth's TwoSum.
         *
         * We can do this because we order the summation from smallest to
         * greatest, so that FastTwoSum can be used without any additional error.
         *
         * The "TwoProduct" exact calculation needs 17 flops. We replace this by
         * a cascaded summation of FastTwoSum calculations, each involving an
         * exact multiply by a power of 2.
         *
         * Doing so saves overall 4 multiplications and 1 addition compared to
         * using traditional "TwoProduct".
         *
         * The scale factor is either 100 (currency case) or 1000 (decimal case).
         * - when 1000, we replace it by (1024 - 16 - 8) = 1000.
         * - when 100,  we replace it by (128  - 32 + 4) =  100.
         * Every multiplication by a power of 2 (1024, 128, 32, 16, 8, 4) is exact.
         *
         */
    double approxMax;    // Will always be positive.
    double approxMedium; // Will always be negative.
    double approxMin;

    double fastTwoSumApproximation = 0.0d;
    double fastTwoSumRoundOff = 0.0d;
    double bVirtual = 0.0d;

    if (isCurrencyFormat) {
      // Scale is 100 = 128 - 32 + 4.
      // Multiply by 2**n is a shift. No roundoff. No error.
      approxMax = fractionalPart * 128.00d;
      approxMedium = -(fractionalPart * 32.00d);
      approxMin = fractionalPart * 4.00d;
    } else {
      // Scale is 1000 = 1024 - 16 - 8.
      // Multiply by 2**n is a shift. No roundoff. No error.
      approxMax = fractionalPart * 1024.00d;
      approxMedium = -(fractionalPart * 16.00d);
      approxMin = -(fractionalPart * 8.00d);
    }

    // Shewchuk/Dekker's FastTwoSum(approxMedium, approxMin).
    assert (-approxMedium >= Math.abs(approxMin));
    fastTwoSumApproximation = approxMedium + approxMin;
    bVirtual = fastTwoSumApproximation - approxMedium;
    fastTwoSumRoundOff = approxMin - bVirtual;
    double approxS1 = fastTwoSumApproximation;
    double roundoffS1 = fastTwoSumRoundOff;

    // Shewchuk/Dekker's FastTwoSum(approxMax, approxS1);
    assert (approxMax >= Math.abs(approxS1));
    fastTwoSumApproximation = approxMax + approxS1;
    bVirtual = fastTwoSumApproximation - approxMax;
    fastTwoSumRoundOff = approxS1 - bVirtual;
    double roundoff1000 = fastTwoSumRoundOff;
    double approx1000 = fastTwoSumApproximation;
    double roundoffTotal = roundoffS1 + roundoff1000;

    // Shewchuk/Dekker's FastTwoSum(approx1000, roundoffTotal);
    assert (approx1000 >= Math.abs(roundoffTotal));
    fastTwoSumApproximation = approx1000 + roundoffTotal;
    bVirtual = fastTwoSumApproximation - approx1000;

    // Now we have got the roundoff for the scaled fractional
    double scaledFractionalRoundoff = roundoffTotal - bVirtual;

    // ---- TwoProduct(fractionalPart, scale (i.e. 1000.0d or 100.0d)) end.

        /* ---- Taking the rounding decision
         *
         * We take rounding decision based on roundoff and half-even rounding
         * rule.
         *
         * The above TwoProduct gives us the exact roundoff on the approximated
         * scaled fractional, and we know that this approximation is exactly
         * 0.5d, since that has already been tested by the caller
         * (fastDoubleFormat).
         *
         * Decision comes first from the sign of the calculated exact roundoff.
         * - Since being exact roundoff, it cannot be positive with a scaled
         *   fractional less than 0.5d, as well as negative with a scaled
         *   fractional greater than 0.5d. That leaves us with following 3 cases.
         * - positive, thus scaled fractional == 0.500....0fff ==> round-up.
         * - negative, thus scaled fractional == 0.499....9fff ==> don't round-up.
         * - is zero,  thus scaled fractioanl == 0.5 ==> half-even rounding applies :
         *    we round-up only if the integral part of the scaled fractional is odd.
         *
         */
    if (scaledFractionalRoundoff > 0.0) {
      return true;
    } else if (scaledFractionalRoundoff < 0.0) {
      return false;
    } else if ((scaledFractionalPartAsInt & 1) != 0) {
      return true;
    }

    return false;

    // ---- Taking the rounding decision end
  }

  /**
   * Collects integral digits from passed {@code number}, while setting
   * grouping chars as needed. Updates {@code firstUsedIndex} accordingly.
   *
   * Loops downward starting from {@code backwardIndex} position (inclusive).
   *
   * @param number The int value from which we collect digits.
   * @param digitsBuffer The char array container where digits and grouping chars are stored.
   * @param backwardIndex the position from which we start storing digits in digitsBuffer.
   */
  private void collectIntegralDigits(int number,
      char[] digitsBuffer,
      int backwardIndex) {
    int index = backwardIndex;
    int q;
    int r;
    while (number > 999) {
      // Generates 3 digits per iteration.
      q = number / 1000;
      r = number - (q << 10) + (q << 4) + (q << 3); // -1024 +16 +8 = 1000.
      number = q;

      digitsBuffer[index--] = DigitArrays.DigitOnes1000[r];
      digitsBuffer[index--] = DigitArrays.DigitTens1000[r];
      digitsBuffer[index--] = DigitArrays.DigitHundreds1000[r];
      digitsBuffer[index--] = fastPathData.groupingChar;
    }

    // Collects last 3 or less digits.
    digitsBuffer[index] = DigitArrays.DigitOnes1000[number];
    if (number > 9) {
      digitsBuffer[--index] = DigitArrays.DigitTens1000[number];
      if (number > 99) {
        digitsBuffer[--index] = DigitArrays.DigitHundreds1000[number];
      }
    }

    fastPathData.firstUsedIndex = index;
  }

  /**
   * Collects the 2 (currency) or 3 (decimal) fractional digits from passed
   * {@code number}, starting at {@code startIndex} position
   * inclusive.  There is no punctuation to set here (no grouping chars).
   * Updates {@code fastPathData.lastFreeIndex} accordingly.
   *
   * @param number The int value from which we collect digits.
   * @param digitsBuffer The char array container where digits are stored.
   * @param startIndex the position from which we start storing digits in digitsBuffer.
   */
  private void collectFractionalDigits(int number,
      char[] digitsBuffer,
      int startIndex) {
    int index = startIndex;

    char digitOnes = DigitArrays.DigitOnes1000[number];
    char digitTens = DigitArrays.DigitTens1000[number];

    if (isCurrencyFormat) {
      // Currency case. Always collects fractional digits.
      digitsBuffer[index++] = digitTens;
      digitsBuffer[index++] = digitOnes;
    } else if (number != 0) {
      // Decimal case. Hundreds will always be collected
      digitsBuffer[index++] = DigitArrays.DigitHundreds1000[number];

      // Ending zeros won't be collected.
      if (digitOnes != '0') {
        digitsBuffer[index++] = digitTens;
        digitsBuffer[index++] = digitOnes;
      } else if (digitTens != '0') {
        digitsBuffer[index++] = digitTens;
      }

    } else
    // This is decimal pattern and fractional part is zero.
    // We must remove decimal point from result.
    {
      index--;
    }

    fastPathData.lastFreeIndex = index;
  }

  /**
   * Internal utility.
   * Adds the passed {@code prefix} and {@code suffix} to {@code container}.
   *
   * @param container Char array container which to prepend/append the prefix/suffix.
   * @param prefix Char sequence to prepend as a prefix.
   * @param suffix Char sequence to append as a suffix.
   */
  //    private void addAffixes(boolean isNegative, char[] container) {
  private void addAffixes(char[] container, char[] prefix, char[] suffix) {

    // We add affixes only if needed (affix length > 0).
    int pl = prefix.length;
    int sl = suffix.length;
    if (pl != 0) {
      prependPrefix(prefix, pl, container);
    }
    if (sl != 0) {
      appendSuffix(suffix, sl, container);
    }

  }

  /**
   * Prepends the passed {@code prefix} chars to given result
   * {@code container}.  Updates {@code fastPathData.firstUsedIndex}
   * accordingly.
   *
   * @param prefix The prefix characters to prepend to result.
   * @param len The number of chars to prepend.
   * @param container Char array container which to prepend the prefix
   */
  private void prependPrefix(char[] prefix,
      int len,
      char[] container) {

    fastPathData.firstUsedIndex -= len;
    int startIndex = fastPathData.firstUsedIndex;

    // If prefix to prepend is only 1 char long, just assigns this char.
    // If prefix is less or equal 4, we use a dedicated algorithm that
    //  has shown to run faster than System.arraycopy.
    // If more than 4, we use System.arraycopy.
    if (len == 1) {
      container[startIndex] = prefix[0];
    } else if (len <= 4) {
      int dstLower = startIndex;
      int dstUpper = dstLower + len - 1;
      int srcUpper = len - 1;
      container[dstLower] = prefix[0];
      container[dstUpper] = prefix[srcUpper];

      if (len > 2) {
        container[++dstLower] = prefix[1];
      }
      if (len == 4) {
        container[--dstUpper] = prefix[2];
      }
    } else {
      System.arraycopy(prefix, 0, container, startIndex, len);
    }
  }

  /**
   * Appends the passed {@code suffix} chars to given result
   * {@code container}.  Updates {@code fastPathData.lastFreeIndex}
   * accordingly.
   *
   * @param suffix The suffix characters to append to result.
   * @param len The number of chars to append.
   * @param container Char array container which to append the suffix
   */
  private void appendSuffix(char[] suffix,
      int len,
      char[] container) {

    int startIndex = fastPathData.lastFreeIndex;

    // If suffix to append is only 1 char long, just assigns this char.
    // If suffix is less or equal 4, we use a dedicated algorithm that
    //  has shown to run faster than System.arraycopy.
    // If more than 4, we use System.arraycopy.
    if (len == 1) {
      container[startIndex] = suffix[0];
    } else if (len <= 4) {
      int dstLower = startIndex;
      int dstUpper = dstLower + len - 1;
      int srcUpper = len - 1;
      container[dstLower] = suffix[0];
      container[dstUpper] = suffix[srcUpper];

      if (len > 2) {
        container[++dstLower] = suffix[1];
      }
      if (len == 4) {
        container[--dstUpper] = suffix[2];
      }
    } else {
      System.arraycopy(suffix, 0, container, startIndex, len);
    }

    fastPathData.lastFreeIndex += len;
  }

  /**
   * Converts digit chars from {@code digitsBuffer} to current locale.
   *
   * Must be called before adding affixes since we refer to
   * {@code fastPathData.firstUsedIndex} and {@code fastPathData.lastFreeIndex},
   * and do not support affixes (for speed reason).
   *
   * We loop backward starting from last used index in {@code fastPathData}.
   *
   * @param digitsBuffer The char array container where the digits are stored.
   */
  private void localizeDigits(char[] digitsBuffer) {

    // We will localize only the digits, using the groupingSize,
    // and taking into account fractional part.

    // First take into account fractional part.
    int digitsCounter =
        fastPathData.lastFreeIndex - fastPathData.fractionalFirstIndex;

    // The case when there is no fractional digits.
    if (digitsCounter < 0) {
      digitsCounter = groupingSize;
    }

    // Only the digits remains to localize.
    for (int cursor = fastPathData.lastFreeIndex - 1;
        cursor >= fastPathData.firstUsedIndex;
        cursor--) {
      if (digitsCounter != 0) {
        // This is a digit char, we must localize it.
        digitsBuffer[cursor] += fastPathData.zeroDelta;
        digitsCounter--;
      } else {
        // Decimal separator or grouping char. Reinit counter only.
        digitsCounter = groupingSize;
      }
    }
  }

  /**
   * This is the main entry point for the fast-path format algorithm.
   *
   * At this point we are sure to be in the expected conditions to run it.
   * This algorithm builds the formatted result and puts it in the dedicated
   * {@code fastPathData.fastPathContainer}.
   *
   * @param d the double value to be formatted.
   * @param negative Flag precising if {@code d} is negative.
   */
  private void fastDoubleFormat(double d,
      boolean negative) {

    char[] container = fastPathData.fastPathContainer;

        /*
         * The principle of the algorithm is to :
         * - Break the passed double into its integral and fractional parts
         *    converted into integers.
         * - Then decide if rounding up must be applied or not by following
         *    the half-even rounding rule, first using approximated scaled
         *    fractional part.
         * - For the difficult cases (approximated scaled fractional part
         *    being exactly 0.5d), we refine the rounding decision by calling
         *    exactRoundUp utility method that both calculates the exact roundoff
         *    on the approximation and takes correct rounding decision.
         * - We round-up the fractional part if needed, possibly propagating the
         *    rounding to integral part if we meet a "all-nine" case for the
         *    scaled fractional part.
         * - We then collect digits from the resulting integral and fractional
         *   parts, also setting the required grouping chars on the fly.
         * - Then we localize the collected digits if needed, and
         * - Finally prepend/append prefix/suffix if any is needed.
         */

    // Exact integral part of d.
    int integralPartAsInt = (int) d;

    // Exact fractional part of d (since we subtract it's integral part).
    double exactFractionalPart = d - (double) integralPartAsInt;

    // Approximated scaled fractional part of d (due to multiplication).
    double scaledFractional =
        exactFractionalPart * fastPathData.fractionalScaleFactor;

    // Exact integral part of scaled fractional above.
    int fractionalPartAsInt = (int) scaledFractional;

    // Exact fractional part of scaled fractional above.
    scaledFractional = scaledFractional - (double) fractionalPartAsInt;

    // Only when scaledFractional is exactly 0.5d do we have to do exact
    // calculations and take fine-grained rounding decision, since
    // approximated results above may lead to incorrect decision.
    // Otherwise comparing against 0.5d (strictly greater or less) is ok.
    boolean roundItUp = false;
    if (scaledFractional >= 0.5d) {
      if (scaledFractional == 0.5d)
      // Rounding need fine-grained decision.
      {
        roundItUp = exactRoundUp(exactFractionalPart, fractionalPartAsInt);
      } else {
        roundItUp = true;
      }

      if (roundItUp) {
        // Rounds up both fractional part (and also integral if needed).
        if (fractionalPartAsInt < fastPathData.fractionalMaxIntBound) {
          fractionalPartAsInt++;
        } else {
          // Propagates rounding to integral part since "all nines" case.
          fractionalPartAsInt = 0;
          integralPartAsInt++;
        }
      }
    }

    // Collecting digits.
    collectFractionalDigits(fractionalPartAsInt, container,
        fastPathData.fractionalFirstIndex);
    collectIntegralDigits(integralPartAsInt, container,
        fastPathData.integralLastIndex);

    // Localizing digits.
    if (fastPathData.zeroDelta != 0) {
      localizeDigits(container);
    }

    // Adding prefix and suffix.
    if (negative) {
      if (fastPathData.negativeAffixesRequired) {
        addAffixes(container,
            fastPathData.charsNegativePrefix,
            fastPathData.charsNegativeSuffix);
      }
    } else if (fastPathData.positiveAffixesRequired) {
      addAffixes(container,
          fastPathData.charsPositivePrefix,
          fastPathData.charsPositiveSuffix);
    }
  }

  /**
   * A fast-path shortcut of format(double) to be called by NumberFormat, or by
   * format(double, ...) public methods.
   *
   * If instance can be applied fast-path and passed double is not NaN or
   * Infinity, is in the integer range, we call {@code fastDoubleFormat}
   * after changing {@code d} to its positive value if necessary.
   *
   * Otherwise returns null by convention since fast-path can't be exercized.
   *
   * @param d The double value to be formatted
   * @return the formatted result for {@code d} as a string.
   */
  String fastFormat(double d) {
    // (Re-)Evaluates fast-path status if needed.
    if (fastPathCheckNeeded) {
      checkAndSetFastPathStatus();
    }

    if (!isFastPath)
    // DecimalFormat instance is not in a fast-path state.
    {
      return null;
    }

    if (!Double.isFinite(d))
    // Should not use fast-path for Infinity and NaN.
    {
      return null;
    }

    // Extracts and records sign of double value, possibly changing it
    // to a positive one, before calling fastDoubleFormat().
    boolean negative = false;
    if (d < 0.0d) {
      negative = true;
      d = -d;
    } else if (d == 0.0d) {
      negative = (Math.copySign(1.0d, d) == -1.0d);
      d = +0.0d;
    }

    if (d > MAX_INT_AS_DOUBLE)
    // Filters out values that are outside expected fast-path range
    {
      return null;
    } else {
      fastDoubleFormat(d, negative);
    }

    // Returns a new string from updated fastPathContainer.
    return new String(fastPathData.fastPathContainer,
        fastPathData.firstUsedIndex,
        fastPathData.lastFreeIndex - fastPathData.firstUsedIndex);

  }

  // ======== End fast-path formating logic for double =========================

  /**
   * Complete the formatting of a finite number.  On entry, the digitList must
   * be filled in with the correct digits.
   */
  private StringBuffer subformat(StringBuffer result, FieldDelegate delegate,
      boolean isNegative, boolean isInteger,
      int maxIntDigits, int minIntDigits,
      int maxFraDigits, int minFraDigits) {
    // NOTE: This isn't required anymore because DigitList takes care of this.
    //
    //  // The negative of the exponent represents the number of leading
    //  // zeros between the decimal and the first non-zero digit, for
    //  // a value < 0.1 (e.g., for 0.00123, -fExponent == 2).  If this
    //  // is more than the maximum fraction digits, then we have an underflow
    //  // for the printed representation.  We recognize this here and set
    //  // the DigitList representation to zero in this situation.
    //
    //  if (-digitList.decimalAt >= getMaximumFractionDigits())
    //  {
    //      digitList.count = 0;
    //  }

    char zero = symbols.getZeroDigit();
    int zeroDelta = zero - '0'; // '0' is the DigitList representation of zero
    char grouping = symbols.getGroupingSeparator();
    char decimal = isCurrencyFormat ?
        symbols.getMonetaryDecimalSeparator() :
        symbols.getDecimalSeparator();

        /* Per bug 4147706, DecimalFormat must respect the sign of numbers which
         * format as zero.  This allows sensible computations and preserves
         * relations such as signum(1/x) = signum(x), where x is +Infinity or
         * -Infinity.  Prior to this fix, we always formatted zero values as if
         * they were positive.  Liu 7/6/98.
         */
    if (digitList.isZero()) {
      digitList.decimalAt = 0; // Normalize
    }

    if (isNegative) {
      append(result, negativePrefix, delegate,
          getNegativePrefixFieldPositions(), Field.SIGN);
    } else {
      append(result, positivePrefix, delegate,
          getPositivePrefixFieldPositions(), Field.SIGN);
    }

    if (useExponentialNotation) {
      int iFieldStart = result.length();
      int iFieldEnd = -1;
      int fFieldStart = -1;

      // Minimum integer digits are handled in exponential format by
      // adjusting the exponent.  For example, 0.01234 with 3 minimum
      // integer digits is "123.4E-4".

      // Maximum integer digits are interpreted as indicating the
      // repeating range.  This is useful for engineering notation, in
      // which the exponent is restricted to a multiple of 3.  For
      // example, 0.01234 with 3 maximum integer digits is "12.34e-3".
      // If maximum integer digits are > 1 and are larger than
      // minimum integer digits, then minimum integer digits are
      // ignored.
      int exponent = digitList.decimalAt;
      int repeat = maxIntDigits;
      int minimumIntegerDigits = minIntDigits;
      if (repeat > 1 && repeat > minIntDigits) {
        // A repeating range is defined; adjust to it as follows.
        // If repeat == 3, we have 6,5,4=>3; 3,2,1=>0; 0,-1,-2=>-3;
        // -3,-4,-5=>-6, etc. This takes into account that the
        // exponent we have here is off by one from what we expect;
        // it is for the format 0.MMMMMx10^n.
        if (exponent >= 1) {
          exponent = ((exponent - 1) / repeat) * repeat;
        } else {
          // integer division rounds towards 0
          exponent = ((exponent - repeat) / repeat) * repeat;
        }
        minimumIntegerDigits = 1;
      } else {
        // No repeating range is defined; use minimum integer digits.
        exponent -= minimumIntegerDigits;
      }

      // We now output a minimum number of digits, and more if there
      // are more digits, up to the maximum number of digits.  We
      // place the decimal point after the "integer" digits, which
      // are the first (decimalAt - exponent) digits.
      int minimumDigits = minIntDigits + minFraDigits;
      if (minimumDigits < 0) {    // overflow?
        minimumDigits = Integer.MAX_VALUE;
      }

      // The number of integer digits is handled specially if the number
      // is zero, since then there may be no digits.
      int integerDigits = digitList.isZero() ? minimumIntegerDigits :
          digitList.decimalAt - exponent;
      if (minimumDigits < integerDigits) {
        minimumDigits = integerDigits;
      }
      int totalDigits = digitList.count;
      if (minimumDigits > totalDigits) {
        totalDigits = minimumDigits;
      }
      boolean addedDecimalSeparator = false;

      for (int i = 0; i < totalDigits; ++i) {
        if (i == integerDigits) {
          // Record field information for caller.
          iFieldEnd = result.length();

          result.append(decimal);
          addedDecimalSeparator = true;

          // Record field information for caller.
          fFieldStart = result.length();
        }
        result.append((i < digitList.count) ?
            (char) (digitList.digits[i] + zeroDelta) :
            zero);
      }

      if (decimalSeparatorAlwaysShown && totalDigits == integerDigits) {
        // Record field information for caller.
        iFieldEnd = result.length();

        result.append(decimal);
        addedDecimalSeparator = true;

        // Record field information for caller.
        fFieldStart = result.length();
      }

      // Record field information
      if (iFieldEnd == -1) {
        iFieldEnd = result.length();
      }
      delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
          iFieldStart, iFieldEnd, result);
      if (addedDecimalSeparator) {
        delegate.formatted(Field.DECIMAL_SEPARATOR,
            Field.DECIMAL_SEPARATOR,
            iFieldEnd, fFieldStart, result);
      }
      if (fFieldStart == -1) {
        fFieldStart = result.length();
      }
      delegate.formatted(FRACTION_FIELD, Field.FRACTION, Field.FRACTION,
          fFieldStart, result.length(), result);

      // The exponent is output using the pattern-specified minimum
      // exponent digits.  There is no maximum limit to the exponent
      // digits, since truncating the exponent would result in an
      // unacceptable inaccuracy.
      int fieldStart = result.length();

      result.append(symbols.getExponentSeparator());

      delegate.formatted(Field.EXPONENT_SYMBOL, Field.EXPONENT_SYMBOL,
          fieldStart, result.length(), result);

      // For zero values, we force the exponent to zero.  We
      // must do this here, and not earlier, because the value
      // is used to determine integer digit count above.
      if (digitList.isZero()) {
        exponent = 0;
      }

      boolean negativeExponent = exponent < 0;
      if (negativeExponent) {
        exponent = -exponent;
        fieldStart = result.length();
        result.append(symbols.getMinusSign());
        delegate.formatted(Field.EXPONENT_SIGN, Field.EXPONENT_SIGN,
            fieldStart, result.length(), result);
      }
      digitList.set(negativeExponent, exponent);

      int eFieldStart = result.length();

      for (int i = digitList.decimalAt; i < minExponentDigits; ++i) {
        result.append(zero);
      }
      for (int i = 0; i < digitList.decimalAt; ++i) {
        result.append((i < digitList.count) ?
            (char) (digitList.digits[i] + zeroDelta) : zero);
      }
      delegate.formatted(Field.EXPONENT, Field.EXPONENT, eFieldStart,
          result.length(), result);
    } else {
      int iFieldStart = result.length();

      // Output the integer portion.  Here 'count' is the total
      // number of integer digits we will display, including both
      // leading zeros required to satisfy getMinimumIntegerDigits,
      // and actual digits present in the number.
      int count = minIntDigits;
      int digitIndex = 0; // Index into digitList.fDigits[]
      if (digitList.decimalAt > 0 && count < digitList.decimalAt) {
        count = digitList.decimalAt;
      }

      // Handle the case where getMaximumIntegerDigits() is smaller
      // than the real number of integer digits.  If this is so, we
      // output the least significant max integer digits.  For example,
      // the value 1997 printed with 2 max integer digits is just "97".
      if (count > maxIntDigits) {
        count = maxIntDigits;
        digitIndex = digitList.decimalAt - count;
      }

      int sizeBeforeIntegerPart = result.length();
      for (int i = count - 1; i >= 0; --i) {
        if (i < digitList.decimalAt && digitIndex < digitList.count) {
          // Output a real digit
          result.append((char) (digitList.digits[digitIndex++] + zeroDelta));
        } else {
          // Output a leading zero
          result.append(zero);
        }

        // Output grouping separator if necessary.  Don't output a
        // grouping separator if i==0 though; that's at the end of
        // the integer part.
        if (isGroupingUsed() && i > 0 && (groupingSize != 0) &&
            (i % groupingSize == 0)) {
          int gStart = result.length();
          result.append(grouping);
          delegate.formatted(Field.GROUPING_SEPARATOR,
              Field.GROUPING_SEPARATOR, gStart,
              result.length(), result);
        }
      }

      // Determine whether or not there are any printable fractional
      // digits.  If we've used up the digits we know there aren't.
      boolean fractionPresent = (minFraDigits > 0) ||
          (!isInteger && digitIndex < digitList.count);

      // If there is no fraction present, and we haven't printed any
      // integer digits, then print a zero.  Otherwise we won't print
      // _any_ digits, and we won't be able to parse this string.
      if (!fractionPresent && result.length() == sizeBeforeIntegerPart) {
        result.append(zero);
      }

      delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
          iFieldStart, result.length(), result);

      // Output the decimal separator if we always do so.
      int sStart = result.length();
      if (decimalSeparatorAlwaysShown || fractionPresent) {
        result.append(decimal);
      }

      if (sStart != result.length()) {
        delegate.formatted(Field.DECIMAL_SEPARATOR,
            Field.DECIMAL_SEPARATOR,
            sStart, result.length(), result);
      }
      int fFieldStart = result.length();

      for (int i = 0; i < maxFraDigits; ++i) {
        // Here is where we escape from the loop.  We escape if we've
        // output the maximum fraction digits (specified in the for
        // expression above).
        // We also stop when we've output the minimum digits and either:
        // we have an integer, so there is no fractional stuff to
        // display, or we're out of significant digits.
        if (i >= minFraDigits &&
            (isInteger || digitIndex >= digitList.count)) {
          break;
        }

        // Output leading fractional zeros. These are zeros that come
        // after the decimal but before any significant digits. These
        // are only output if abs(number being formatted) < 1.0.
        if (-1 - i > (digitList.decimalAt - 1)) {
          result.append(zero);
          continue;
        }

        // Output a digit, if we have any precision left, or a
        // zero if we don't.  We don't want to output noise digits.
        if (!isInteger && digitIndex < digitList.count) {
          result.append((char) (digitList.digits[digitIndex++] + zeroDelta));
        } else {
          result.append(zero);
        }
      }

      // Record field information for caller.
      delegate.formatted(FRACTION_FIELD, Field.FRACTION, Field.FRACTION,
          fFieldStart, result.length(), result);
    }

    if (isNegative) {
      append(result, negativeSuffix, delegate,
          getNegativeSuffixFieldPositions(), Field.SIGN);
    } else {
      append(result, positiveSuffix, delegate,
          getPositiveSuffixFieldPositions(), Field.SIGN);
    }

    return result;
  }

  /**
   * Appends the String <code>string</code> to <code>result</code>.
   * <code>delegate</code> is notified of all  the
   * <code>FieldPosition</code>s in <code>positions</code>.
   * <p>
   * If one of the <code>FieldPosition</code>s in <code>positions</code>
   * identifies a <code>SIGN</code> attribute, it is mapped to
   * <code>signAttribute</code>. This is used
   * to map the <code>SIGN</code> attribute to the <code>EXPONENT</code>
   * attribute as necessary.
   * <p>
   * This is used by <code>subformat</code> to add the prefix/suffix.
   */
  private void append(StringBuffer result, String string,
      FieldDelegate delegate,
      FieldPosition[] positions,
      Format.Field signAttribute) {
    int start = result.length();

    if (string.length() > 0) {
      result.append(string);
      for (int counter = 0, max = positions.length; counter < max;
          counter++) {
        FieldPosition fp = positions[counter];
        Format.Field attribute = fp.getFieldAttribute();

        if (attribute == Field.SIGN) {
          attribute = signAttribute;
        }
        delegate.formatted(attribute, attribute,
            start + fp.getBeginIndex(),
            start + fp.getEndIndex(), result);
      }
    }
  }

  /**
   * Parses text from a string to produce a <code>Number</code>.
   * <p>
   * The method attempts to parse text starting at the index given by
   * <code>pos</code>.
   * If parsing succeeds, then the index of <code>pos</code> is updated
   * to the index after the last character used (parsing does not necessarily
   * use all characters up to the end of the string), and the parsed
   * number is returned. The updated <code>pos</code> can be used to
   * indicate the starting point for the next call to this method.
   * If an error occurs, then the index of <code>pos</code> is not
   * changed, the error index of <code>pos</code> is set to the index of
   * the character where the error occurred, and null is returned.
   * <p>
   * The subclass returned depends on the value of {@link #isParseBigDecimal}
   * as well as on the string being parsed.
   * <ul>
   * <li>If <code>isParseBigDecimal()</code> is false (the default),
   * most integer values are returned as <code>Long</code>
   * objects, no matter how they are written: <code>"17"</code> and
   * <code>"17.000"</code> both parse to <code>Long(17)</code>.
   * Values that cannot fit into a <code>Long</code> are returned as
   * <code>Double</code>s. This includes values with a fractional part,
   * infinite values, <code>NaN</code>, and the value -0.0.
   * <code>DecimalFormat</code> does <em>not</em> decide whether to
   * return a <code>Double</code> or a <code>Long</code> based on the
   * presence of a decimal separator in the source string. Doing so
   * would prevent integers that overflow the mantissa of a double,
   * such as <code>"-9,223,372,036,854,775,808.00"</code>, from being
   * parsed accurately.
   * <p>
   * Callers may use the <code>Number</code> methods
   * <code>doubleValue</code>, <code>longValue</code>, etc., to obtain
   * the type they want.
   * <li>If <code>isParseBigDecimal()</code> is true, values are returned
   * as <code>BigDecimal</code> objects. The values are the ones
   * constructed by {@link java.math.BigDecimal#BigDecimal(String)}
   * for corresponding strings in locale-independent format. The
   * special cases negative and positive infinity and NaN are returned
   * as <code>Double</code> instances holding the values of the
   * corresponding <code>Double</code> constants.
   * </ul>
   * <p>
   * <code>DecimalFormat</code> parses all Unicode characters that represent
   * decimal digits, as defined by <code>Character.digit()</code>. In
   * addition, <code>DecimalFormat</code> also recognizes as digits the ten
   * consecutive characters starting with the localized zero digit defined in
   * the <code>DecimalFormatSymbols</code> object.
   *
   * @param text the string to be parsed
   * @param pos A <code>ParsePosition</code> object with index and error index information as
   * described above.
   * @return the parsed value, or <code>null</code> if the parse fails
   * @throws NullPointerException if <code>text</code> or <code>pos</code> is null.
   */
  @Override
  public Number parse(String text, ParsePosition pos) {
    // special case NaN
    if (text.regionMatches(pos.index, symbols.getNaN(), 0, symbols.getNaN().length())) {
      pos.index = pos.index + symbols.getNaN().length();
      return new Double(Double.NaN);
    }

    boolean[] status = new boolean[STATUS_LENGTH];
    if (!subparse(text, pos, positivePrefix, negativePrefix, digitList, false, status)) {
      return null;
    }

    // special case INFINITY
    if (status[STATUS_INFINITE]) {
      if (status[STATUS_POSITIVE] == (multiplier >= 0)) {
        return new Double(Double.POSITIVE_INFINITY);
      } else {
        return new Double(Double.NEGATIVE_INFINITY);
      }
    }

    if (multiplier == 0) {
      if (digitList.isZero()) {
        return new Double(Double.NaN);
      } else if (status[STATUS_POSITIVE]) {
        return new Double(Double.POSITIVE_INFINITY);
      } else {
        return new Double(Double.NEGATIVE_INFINITY);
      }
    }

    if (isParseBigDecimal()) {
      BigDecimal bigDecimalResult = digitList.getBigDecimal();

      if (multiplier != 1) {
        try {
          bigDecimalResult = bigDecimalResult.divide(getBigDecimalMultiplier());
        } catch (ArithmeticException e) {  // non-terminating decimal expansion
          bigDecimalResult = bigDecimalResult.divide(getBigDecimalMultiplier(), roundingMode);
        }
      }

      if (!status[STATUS_POSITIVE]) {
        bigDecimalResult = bigDecimalResult.negate();
      }
      return bigDecimalResult;
    } else {
      boolean gotDouble = true;
      boolean gotLongMinimum = false;
      double doubleResult = 0.0;
      long longResult = 0;

      // Finally, have DigitList parse the digits into a value.
      if (digitList.fitsIntoLong(status[STATUS_POSITIVE], isParseIntegerOnly())) {
        gotDouble = false;
        longResult = digitList.getLong();
        if (longResult < 0) {  // got Long.MIN_VALUE
          gotLongMinimum = true;
        }
      } else {
        doubleResult = digitList.getDouble();
      }

      // Divide by multiplier. We have to be careful here not to do
      // unneeded conversions between double and long.
      if (multiplier != 1) {
        if (gotDouble) {
          doubleResult /= multiplier;
        } else {
          // Avoid converting to double if we can
          if (longResult % multiplier == 0) {
            longResult /= multiplier;
          } else {
            doubleResult = ((double) longResult) / multiplier;
            gotDouble = true;
          }
        }
      }

      if (!status[STATUS_POSITIVE] && !gotLongMinimum) {
        doubleResult = -doubleResult;
        longResult = -longResult;
      }

      // At this point, if we divided the result by the multiplier, the
      // result may fit into a long.  We check for this case and return
      // a long if possible.
      // We must do this AFTER applying the negative (if appropriate)
      // in order to handle the case of LONG_MIN; otherwise, if we do
      // this with a positive value -LONG_MIN, the double is > 0, but
      // the long is < 0. We also must retain a double in the case of
      // -0.0, which will compare as == to a long 0 cast to a double
      // (bug 4162852).
      if (multiplier != 1 && gotDouble) {
        longResult = (long) doubleResult;
        gotDouble = ((doubleResult != (double) longResult) ||
            (doubleResult == 0.0 && 1 / doubleResult < 0.0)) &&
            !isParseIntegerOnly();
      }

      return gotDouble ?
          (Number) new Double(doubleResult) : (Number) new Long(longResult);
    }
  }

  /**
   * Return a BigInteger multiplier.
   */
  private BigInteger getBigIntegerMultiplier() {
    if (bigIntegerMultiplier == null) {
      bigIntegerMultiplier = BigInteger.valueOf(multiplier);
    }
    return bigIntegerMultiplier;
  }

  private transient BigInteger bigIntegerMultiplier;

  /**
   * Return a BigDecimal multiplier.
   */
  private BigDecimal getBigDecimalMultiplier() {
    if (bigDecimalMultiplier == null) {
      bigDecimalMultiplier = new BigDecimal(multiplier);
    }
    return bigDecimalMultiplier;
  }

  private transient BigDecimal bigDecimalMultiplier;

  private static final int STATUS_INFINITE = 0;
  private static final int STATUS_POSITIVE = 1;
  private static final int STATUS_LENGTH = 2;

  /**
   * Parse the given text into a number.  The text is parsed beginning at
   * parsePosition, until an unparseable character is seen.
   *
   * @param text The string to parse.
   * @param parsePosition The position at which to being parsing.  Upon return, the first
   * unparseable character.
   * @param digits The DigitList to set to the parsed value.
   * @param isExponent If true, parse an exponent.  This means no infinite values and integer only.
   * @param status Upon return contains boolean status flags indicating whether the value was
   * infinite and whether it was positive.
   */
  private final boolean subparse(String text, ParsePosition parsePosition,
      String positivePrefix, String negativePrefix,
      DigitList digits, boolean isExponent,
      boolean status[]) {
    int position = parsePosition.index;
    int oldStart = parsePosition.index;
    int backup;
    boolean gotPositive, gotNegative;

    // check for positivePrefix; take longest
    gotPositive = text.regionMatches(position, positivePrefix, 0,
        positivePrefix.length());
    gotNegative = text.regionMatches(position, negativePrefix, 0,
        negativePrefix.length());

    if (gotPositive && gotNegative) {
      if (positivePrefix.length() > negativePrefix.length()) {
        gotNegative = false;
      } else if (positivePrefix.length() < negativePrefix.length()) {
        gotPositive = false;
      }
    }

    if (gotPositive) {
      position += positivePrefix.length();
    } else if (gotNegative) {
      position += negativePrefix.length();
    } else {
      parsePosition.errorIndex = position;
      return false;
    }

    // process digits or Inf, find decimal position
    status[STATUS_INFINITE] = false;
    if (!isExponent && text.regionMatches(position, symbols.getInfinity(), 0,
        symbols.getInfinity().length())) {
      position += symbols.getInfinity().length();
      status[STATUS_INFINITE] = true;
    } else {
      // We now have a string of digits, possibly with grouping symbols,
      // and decimal points.  We want to process these into a DigitList.
      // We don't want to put a bunch of leading zeros into the DigitList
      // though, so we keep track of the location of the decimal point,
      // put only significant digits into the DigitList, and adjust the
      // exponent as needed.

      digits.decimalAt = digits.count = 0;
      char zero = symbols.getZeroDigit();
      char decimal = isCurrencyFormat ?
          symbols.getMonetaryDecimalSeparator() :
          symbols.getDecimalSeparator();
      char grouping = symbols.getGroupingSeparator();
      String exponentString = symbols.getExponentSeparator();
      boolean sawDecimal = false;
      boolean sawExponent = false;
      boolean sawDigit = false;
      int exponent = 0; // Set to the exponent value, if any

      // We have to track digitCount ourselves, because digits.count will
      // pin when the maximum allowable digits is reached.
      int digitCount = 0;

      backup = -1;
      for (; position < text.length(); ++position) {
        char ch = text.charAt(position);

                /* We recognize all digit ranges, not only the Latin digit range
                 * '0'..'9'.  We do so by using the Character.digit() method,
                 * which converts a valid Unicode digit to the range 0..9.
                 *
                 * The character 'ch' may be a digit.  If so, place its value
                 * from 0 to 9 in 'digit'.  First try using the locale digit,
                 * which may or MAY NOT be a standard Unicode digit range.  If
                 * this fails, try using the standard Unicode digit ranges by
                 * calling Character.digit().  If this also fails, digit will
                 * have a value outside the range 0..9.
                 */
        int digit = ch - zero;
        if (digit < 0 || digit > 9) {
          digit = Character.digit(ch, 10);
        }

        if (digit == 0) {
          // Cancel out backup setting (see grouping handler below)
          backup = -1; // Do this BEFORE continue statement below!!!
          sawDigit = true;

          // Handle leading zeros
          if (digits.count == 0) {
            // Ignore leading zeros in integer part of number.
            if (!sawDecimal) {
              continue;
            }

            // If we have seen the decimal, but no significant
            // digits yet, then we account for leading zeros by
            // decrementing the digits.decimalAt into negative
            // values.
            --digits.decimalAt;
          } else {
            ++digitCount;
            digits.append((char) (digit + '0'));
          }
        } else if (digit > 0 && digit <= 9) { // [sic] digit==0 handled above
          sawDigit = true;
          ++digitCount;
          digits.append((char) (digit + '0'));

          // Cancel out backup setting (see grouping handler below)
          backup = -1;
        } else if (!isExponent && ch == decimal) {
          // If we're only parsing integers, or if we ALREADY saw the
          // decimal, then don't parse this one.
          if (isParseIntegerOnly() || sawDecimal) {
            break;
          }
          digits.decimalAt = digitCount; // Not digits.count!
          sawDecimal = true;
        } else if (!isExponent && ch == grouping && isGroupingUsed()) {
          if (sawDecimal) {
            break;
          }
          // Ignore grouping characters, if we are using them, but
          // require that they be followed by a digit.  Otherwise
          // we backup and reprocess them.
          backup = position;
        } else if (!isExponent && text
            .regionMatches(position, exponentString, 0, exponentString.length())
            && !sawExponent) {
          // Process the exponent by recursively calling this method.
          ParsePosition pos = new ParsePosition(position + exponentString.length());
          boolean[] stat = new boolean[STATUS_LENGTH];
          DigitList exponentDigits = new DigitList();

          if (subparse(text, pos, "", Character.toString(symbols.getMinusSign()), exponentDigits,
              true, stat) &&
              exponentDigits.fitsIntoLong(stat[STATUS_POSITIVE], true)) {
            position = pos.index; // Advance past the exponent
            exponent = (int) exponentDigits.getLong();
            if (!stat[STATUS_POSITIVE]) {
              exponent = -exponent;
            }
            sawExponent = true;
          }
          break; // Whether we fail or succeed, we exit this loop
        } else {
          break;
        }
      }

      if (backup != -1) {
        position = backup;
      }

      // If there was no decimal point we have an integer
      if (!sawDecimal) {
        digits.decimalAt = digitCount; // Not digits.count!
      }

      // Adjust for exponent, if any
      digits.decimalAt += exponent;

      // If none of the text string was recognized.  For example, parse
      // "x" with pattern "#0.00" (return index and error index both 0)
      // parse "$" with pattern "$#0.00". (return index 0 and error
      // index 1).
      if (!sawDigit && digitCount == 0) {
        parsePosition.index = oldStart;
        parsePosition.errorIndex = oldStart;
        return false;
      }
    }

    // check for suffix
    if (!isExponent) {
      if (gotPositive) {
        gotPositive = text.regionMatches(position, positiveSuffix, 0,
            positiveSuffix.length());
      }
      if (gotNegative) {
        gotNegative = text.regionMatches(position, negativeSuffix, 0,
            negativeSuffix.length());
      }

      // if both match, take longest
      if (gotPositive && gotNegative) {
        if (positiveSuffix.length() > negativeSuffix.length()) {
          gotNegative = false;
        } else if (positiveSuffix.length() < negativeSuffix.length()) {
          gotPositive = false;
        }
      }

      // fail if neither or both
      if (gotPositive == gotNegative) {
        parsePosition.errorIndex = position;
        return false;
      }

      parsePosition.index = position +
          (gotPositive ? positiveSuffix.length() : negativeSuffix.length()); // mark success!
    } else {
      parsePosition.index = position;
    }

    status[STATUS_POSITIVE] = gotPositive;
    if (parsePosition.index == oldStart) {
      parsePosition.errorIndex = position;
      return false;
    }
    return true;
  }

  /**
   * Returns a copy of the decimal format symbols, which is generally not
   * changed by the programmer or user.
   *
   * @return a copy of the desired DecimalFormatSymbols
   * @see java.text.DecimalFormatSymbols
   */
  public DecimalFormatSymbols getDecimalFormatSymbols() {
    try {
      // don't allow multiple references
      return (DecimalFormatSymbols) symbols.clone();
    } catch (Exception foo) {
      return null; // should never happen
    }
  }


  /**
   * Sets the decimal format symbols, which is generally not changed
   * by the programmer or user.
   *
   * @param newSymbols desired DecimalFormatSymbols
   * @see java.text.DecimalFormatSymbols
   */
  public void setDecimalFormatSymbols(DecimalFormatSymbols newSymbols) {
    try {
      // don't allow multiple references
      symbols = (DecimalFormatSymbols) newSymbols.clone();
      expandAffixes();
      fastPathCheckNeeded = true;
    } catch (Exception foo) {
      // should never happen
    }
  }

  /**
   * Get the positive prefix.
   * <P>Examples: +123, $123, sFr123
   *
   * @return the positive prefix
   */
  public String getPositivePrefix() {
    return positivePrefix;
  }

  /**
   * Set the positive prefix.
   * <P>Examples: +123, $123, sFr123
   *
   * @param newValue the new positive prefix
   */
  public void setPositivePrefix(String newValue) {
    positivePrefix = newValue;
    posPrefixPattern = null;
    positivePrefixFieldPositions = null;
    fastPathCheckNeeded = true;
  }

  /**
   * Returns the FieldPositions of the fields in the prefix used for
   * positive numbers. This is not used if the user has explicitly set
   * a positive prefix via <code>setPositivePrefix</code>. This is
   * lazily created.
   *
   * @return FieldPositions in positive prefix
   */
  private FieldPosition[] getPositivePrefixFieldPositions() {
    if (positivePrefixFieldPositions == null) {
      if (posPrefixPattern != null) {
        positivePrefixFieldPositions = expandAffix(posPrefixPattern);
      } else {
        positivePrefixFieldPositions = EmptyFieldPositionArray;
      }
    }
    return positivePrefixFieldPositions;
  }

  /**
   * Get the negative prefix.
   * <P>Examples: -123, ($123) (with negative suffix), sFr-123
   *
   * @return the negative prefix
   */
  public String getNegativePrefix() {
    return negativePrefix;
  }

  /**
   * Set the negative prefix.
   * <P>Examples: -123, ($123) (with negative suffix), sFr-123
   *
   * @param newValue the new negative prefix
   */
  public void setNegativePrefix(String newValue) {
    negativePrefix = newValue;
    negPrefixPattern = null;
    fastPathCheckNeeded = true;
  }

  /**
   * Returns the FieldPositions of the fields in the prefix used for
   * negative numbers. This is not used if the user has explicitly set
   * a negative prefix via <code>setNegativePrefix</code>. This is
   * lazily created.
   *
   * @return FieldPositions in positive prefix
   */
  private FieldPosition[] getNegativePrefixFieldPositions() {
    if (negativePrefixFieldPositions == null) {
      if (negPrefixPattern != null) {
        negativePrefixFieldPositions = expandAffix(negPrefixPattern);
      } else {
        negativePrefixFieldPositions = EmptyFieldPositionArray;
      }
    }
    return negativePrefixFieldPositions;
  }

  /**
   * Get the positive suffix.
   * <P>Example: 123%
   *
   * @return the positive suffix
   */
  public String getPositiveSuffix() {
    return positiveSuffix;
  }

  /**
   * Set the positive suffix.
   * <P>Example: 123%
   *
   * @param newValue the new positive suffix
   */
  public void setPositiveSuffix(String newValue) {
    positiveSuffix = newValue;
    posSuffixPattern = null;
    fastPathCheckNeeded = true;
  }

  /**
   * Returns the FieldPositions of the fields in the suffix used for
   * positive numbers. This is not used if the user has explicitly set
   * a positive suffix via <code>setPositiveSuffix</code>. This is
   * lazily created.
   *
   * @return FieldPositions in positive prefix
   */
  private FieldPosition[] getPositiveSuffixFieldPositions() {
    if (positiveSuffixFieldPositions == null) {
      if (posSuffixPattern != null) {
        positiveSuffixFieldPositions = expandAffix(posSuffixPattern);
      } else {
        positiveSuffixFieldPositions = EmptyFieldPositionArray;
      }
    }
    return positiveSuffixFieldPositions;
  }

  /**
   * Get the negative suffix.
   * <P>Examples: -123%, ($123) (with positive suffixes)
   *
   * @return the negative suffix
   */
  public String getNegativeSuffix() {
    return negativeSuffix;
  }

  /**
   * Set the negative suffix.
   * <P>Examples: 123%
   *
   * @param newValue the new negative suffix
   */
  public void setNegativeSuffix(String newValue) {
    negativeSuffix = newValue;
    negSuffixPattern = null;
    fastPathCheckNeeded = true;
  }

  /**
   * Returns the FieldPositions of the fields in the suffix used for
   * negative numbers. This is not used if the user has explicitly set
   * a negative suffix via <code>setNegativeSuffix</code>. This is
   * lazily created.
   *
   * @return FieldPositions in positive prefix
   */
  private FieldPosition[] getNegativeSuffixFieldPositions() {
    if (negativeSuffixFieldPositions == null) {
      if (negSuffixPattern != null) {
        negativeSuffixFieldPositions = expandAffix(negSuffixPattern);
      } else {
        negativeSuffixFieldPositions = EmptyFieldPositionArray;
      }
    }
    return negativeSuffixFieldPositions;
  }

  /**
   * Gets the multiplier for use in percent, per mille, and similar
   * formats.
   *
   * @return the multiplier
   * @see #setMultiplier(int)
   */
  public int getMultiplier() {
    return multiplier;
  }

  /**
   * Sets the multiplier for use in percent, per mille, and similar
   * formats.
   * For a percent format, set the multiplier to 100 and the suffixes to
   * have '%' (for Arabic, use the Arabic percent sign).
   * For a per mille format, set the multiplier to 1000 and the suffixes to
   * have '&#92;u2030'.
   *
   * <P>Example: with multiplier 100, 1.23 is formatted as "123", and
   * "123" is parsed into 1.23.
   *
   * @param newValue the new multiplier
   * @see #getMultiplier
   */
  public void setMultiplier(int newValue) {
    multiplier = newValue;
    bigDecimalMultiplier = null;
    bigIntegerMultiplier = null;
    fastPathCheckNeeded = true;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public void setGroupingUsed(boolean newValue) {
    super.setGroupingUsed(newValue);
    fastPathCheckNeeded = true;
  }

  /**
   * Return the grouping size. Grouping size is the number of digits between
   * grouping separators in the integer portion of a number.  For example,
   * in the number "123,456.78", the grouping size is 3.
   *
   * @return the grouping size
   * @see #setGroupingSize
   * @see java.text.NumberFormat#isGroupingUsed
   * @see java.text.DecimalFormatSymbols#getGroupingSeparator
   */
  public int getGroupingSize() {
    return groupingSize;
  }

  /**
   * Set the grouping size. Grouping size is the number of digits between
   * grouping separators in the integer portion of a number.  For example,
   * in the number "123,456.78", the grouping size is 3.
   * <br>
   * The value passed in is converted to a byte, which may lose information.
   *
   * @param newValue the new grouping size
   * @see #getGroupingSize
   * @see java.text.NumberFormat#setGroupingUsed
   * @see java.text.DecimalFormatSymbols#setGroupingSeparator
   */
  public void setGroupingSize(int newValue) {
    groupingSize = (byte) newValue;
    fastPathCheckNeeded = true;
  }

  /**
   * Allows you to get the behavior of the decimal separator with integers.
   * (The decimal separator will always appear with decimals.)
   * <P>Example: Decimal ON: 12345 &rarr; 12345.; OFF: 12345 &rarr; 12345
   *
   * @return {@code true} if the decimal separator is always shown; {@code false} otherwise
   */
  public boolean isDecimalSeparatorAlwaysShown() {
    return decimalSeparatorAlwaysShown;
  }

  /**
   * Allows you to set the behavior of the decimal separator with integers.
   * (The decimal separator will always appear with decimals.)
   * <P>Example: Decimal ON: 12345 &rarr; 12345.; OFF: 12345 &rarr; 12345
   *
   * @param newValue {@code true} if the decimal separator is always shown; {@code false} otherwise
   */
  public void setDecimalSeparatorAlwaysShown(boolean newValue) {
    decimalSeparatorAlwaysShown = newValue;
    fastPathCheckNeeded = true;
  }

  /**
   * Returns whether the {@link #parse(java.lang.String, java.text.ParsePosition)}
   * method returns <code>BigDecimal</code>. The default value is false.
   *
   * @return {@code true} if the parse method returns BigDecimal; {@code false} otherwise
   * @see #setParseBigDecimal
   * @since 1.5
   */
  public boolean isParseBigDecimal() {
    return parseBigDecimal;
  }

  /**
   * Sets whether the {@link #parse(java.lang.String, java.text.ParsePosition)}
   * method returns <code>BigDecimal</code>.
   *
   * @param newValue {@code true} if the parse method returns BigDecimal; {@code false} otherwise
   * @see #isParseBigDecimal
   * @since 1.5
   */
  public void setParseBigDecimal(boolean newValue) {
    parseBigDecimal = newValue;
  }

  /**
   * Standard override; no change in semantics.
   */
  @Override
  public Object clone() {
    DecimalFormat other = (DecimalFormat) super.clone();
    other.symbols = (DecimalFormatSymbols) symbols.clone();
    other.digitList = (DigitList) digitList.clone();

    // Fast-path is almost stateless algorithm. The only logical state is the
    // isFastPath flag. In addition fastPathCheckNeeded is a sentinel flag
    // that forces recalculation of all fast-path fields when set to true.
    //
    // There is thus no need to clone all the fast-path fields.
    // We just only need to set fastPathCheckNeeded to true when cloning,
    // and init fastPathData to null as if it were a truly new instance.
    // Every fast-path field will be recalculated (only once) at next usage of
    // fast-path algorithm.
    other.fastPathCheckNeeded = true;
    other.isFastPath = false;
    other.fastPathData = null;

    return other;
  }

  /**
   * Overrides equals
   */
  @Override
  public boolean equals(Object obj) {
    if (obj == null) {
      return false;
    }
    if (!super.equals(obj)) {
      return false; // super does class check
    }
    DecimalFormat other = (DecimalFormat) obj;
    return ((posPrefixPattern == other.posPrefixPattern &&
        positivePrefix.equals(other.positivePrefix))
        || (posPrefixPattern != null &&
        posPrefixPattern.equals(other.posPrefixPattern)))
        && ((posSuffixPattern == other.posSuffixPattern &&
        positiveSuffix.equals(other.positiveSuffix))
        || (posSuffixPattern != null &&
        posSuffixPattern.equals(other.posSuffixPattern)))
        && ((negPrefixPattern == other.negPrefixPattern &&
        negativePrefix.equals(other.negativePrefix))
        || (negPrefixPattern != null &&
        negPrefixPattern.equals(other.negPrefixPattern)))
        && ((negSuffixPattern == other.negSuffixPattern &&
        negativeSuffix.equals(other.negativeSuffix))
        || (negSuffixPattern != null &&
        negSuffixPattern.equals(other.negSuffixPattern)))
        && multiplier == other.multiplier
        && groupingSize == other.groupingSize
        && decimalSeparatorAlwaysShown == other.decimalSeparatorAlwaysShown
        && parseBigDecimal == other.parseBigDecimal
        && useExponentialNotation == other.useExponentialNotation
        && (!useExponentialNotation ||
        minExponentDigits == other.minExponentDigits)
        && maximumIntegerDigits == other.maximumIntegerDigits
        && minimumIntegerDigits == other.minimumIntegerDigits
        && maximumFractionDigits == other.maximumFractionDigits
        && minimumFractionDigits == other.minimumFractionDigits
        && roundingMode == other.roundingMode
        && symbols.equals(other.symbols);
  }

  /**
   * Overrides hashCode
   */
  @Override
  public int hashCode() {
    return super.hashCode() * 37 + positivePrefix.hashCode();
    // just enough fields for a reasonable distribution
  }

  /**
   * Synthesizes a pattern string that represents the current state
   * of this Format object.
   *
   * @return a pattern string
   * @see #applyPattern
   */
  public String toPattern() {
    return toPattern(false);
  }

  /**
   * Synthesizes a localized pattern string that represents the current
   * state of this Format object.
   *
   * @return a localized pattern string
   * @see #applyPattern
   */
  public String toLocalizedPattern() {
    return toPattern(true);
  }

  /**
   * Expand the affix pattern strings into the expanded affix strings.  If any
   * affix pattern string is null, do not expand it.  This method should be
   * called any time the symbols or the affix patterns change in order to keep
   * the expanded affix strings up to date.
   */
  private void expandAffixes() {
    // Reuse one StringBuffer for better performance
    StringBuffer buffer = new StringBuffer();
    if (posPrefixPattern != null) {
      positivePrefix = expandAffix(posPrefixPattern, buffer);
      positivePrefixFieldPositions = null;
    }
    if (posSuffixPattern != null) {
      positiveSuffix = expandAffix(posSuffixPattern, buffer);
      positiveSuffixFieldPositions = null;
    }
    if (negPrefixPattern != null) {
      negativePrefix = expandAffix(negPrefixPattern, buffer);
      negativePrefixFieldPositions = null;
    }
    if (negSuffixPattern != null) {
      negativeSuffix = expandAffix(negSuffixPattern, buffer);
      negativeSuffixFieldPositions = null;
    }
  }

  /**
   * Expand an affix pattern into an affix string.  All characters in the
   * pattern are literal unless prefixed by QUOTE.  The following characters
   * after QUOTE are recognized: PATTERN_PERCENT, PATTERN_PER_MILLE,
   * PATTERN_MINUS, and CURRENCY_SIGN.  If CURRENCY_SIGN is doubled (QUOTE +
   * CURRENCY_SIGN + CURRENCY_SIGN), it is interpreted as an ISO 4217
   * currency code.  Any other character after a QUOTE represents itself.
   * QUOTE must be followed by another character; QUOTE may not occur by
   * itself at the end of the pattern.
   *
   * @param pattern the non-null, possibly empty pattern
   * @param buffer a scratch StringBuffer; its contents will be lost
   * @return the expanded equivalent of pattern
   */
  private String expandAffix(String pattern, StringBuffer buffer) {
    buffer.setLength(0);
    for (int i = 0; i < pattern.length(); ) {
      char c = pattern.charAt(i++);
      if (c == QUOTE) {
        c = pattern.charAt(i++);
        switch (c) {
          case CURRENCY_SIGN:
            if (i < pattern.length() &&
                pattern.charAt(i) == CURRENCY_SIGN) {
              ++i;
              buffer.append(symbols.getInternationalCurrencySymbol());
            } else {
              buffer.append(symbols.getCurrencySymbol());
            }
            continue;
          case PATTERN_PERCENT:
            c = symbols.getPercent();
            break;
          case PATTERN_PER_MILLE:
            c = symbols.getPerMill();
            break;
          case PATTERN_MINUS:
            c = symbols.getMinusSign();
            break;
        }
      }
      buffer.append(c);
    }
    return buffer.toString();
  }

  /**
   * Expand an affix pattern into an array of FieldPositions describing
   * how the pattern would be expanded.
   * All characters in the
   * pattern are literal unless prefixed by QUOTE.  The following characters
   * after QUOTE are recognized: PATTERN_PERCENT, PATTERN_PER_MILLE,
   * PATTERN_MINUS, and CURRENCY_SIGN.  If CURRENCY_SIGN is doubled (QUOTE +
   * CURRENCY_SIGN + CURRENCY_SIGN), it is interpreted as an ISO 4217
   * currency code.  Any other character after a QUOTE represents itself.
   * QUOTE must be followed by another character; QUOTE may not occur by
   * itself at the end of the pattern.
   *
   * @param pattern the non-null, possibly empty pattern
   * @return FieldPosition array of the resulting fields.
   */
  private FieldPosition[] expandAffix(String pattern) {
    ArrayList<FieldPosition> positions = null;
    int stringIndex = 0;
    for (int i = 0; i < pattern.length(); ) {
      char c = pattern.charAt(i++);
      if (c == QUOTE) {
        int field = -1;
        Format.Field fieldID = null;
        c = pattern.charAt(i++);
        switch (c) {
          case CURRENCY_SIGN:
            String string;
            if (i < pattern.length() &&
                pattern.charAt(i) == CURRENCY_SIGN) {
              ++i;
              string = symbols.getInternationalCurrencySymbol();
            } else {
              string = symbols.getCurrencySymbol();
            }
            if (string.length() > 0) {
              if (positions == null) {
                positions = new ArrayList<>(2);
              }
              FieldPosition fp = new FieldPosition(Field.CURRENCY);
              fp.setBeginIndex(stringIndex);
              fp.setEndIndex(stringIndex + string.length());
              positions.add(fp);
              stringIndex += string.length();
            }
            continue;
          case PATTERN_PERCENT:
            c = symbols.getPercent();
            field = -1;
            fieldID = Field.PERCENT;
            break;
          case PATTERN_PER_MILLE:
            c = symbols.getPerMill();
            field = -1;
            fieldID = Field.PERMILLE;
            break;
          case PATTERN_MINUS:
            c = symbols.getMinusSign();
            field = -1;
            fieldID = Field.SIGN;
            break;
        }
        if (fieldID != null) {
          if (positions == null) {
            positions = new ArrayList<>(2);
          }
          FieldPosition fp = new FieldPosition(fieldID, field);
          fp.setBeginIndex(stringIndex);
          fp.setEndIndex(stringIndex + 1);
          positions.add(fp);
        }
      }
      stringIndex++;
    }
    if (positions != null) {
      return positions.toArray(EmptyFieldPositionArray);
    }
    return EmptyFieldPositionArray;
  }

  /**
   * Appends an affix pattern to the given StringBuffer, quoting special
   * characters as needed.  Uses the internal affix pattern, if that exists,
   * or the literal affix, if the internal affix pattern is null.  The
   * appended string will generate the same affix pattern (or literal affix)
   * when passed to toPattern().
   *
   * @param buffer the affix string is appended to this
   * @param affixPattern a pattern such as posPrefixPattern; may be null
   * @param expAffix a corresponding expanded affix, such as positivePrefix. Ignored unless
   * affixPattern is null.  If affixPattern is null, then expAffix is appended as a literal affix.
   * @param localized true if the appended pattern should contain localized pattern characters;
   * otherwise, non-localized pattern chars are appended
   */
  private void appendAffix(StringBuffer buffer, String affixPattern,
      String expAffix, boolean localized) {
    if (affixPattern == null) {
      appendAffix(buffer, expAffix, localized);
    } else {
      int i;
      for (int pos = 0; pos < affixPattern.length(); pos = i) {
        i = affixPattern.indexOf(QUOTE, pos);
        if (i < 0) {
          appendAffix(buffer, affixPattern.substring(pos), localized);
          break;
        }
        if (i > pos) {
          appendAffix(buffer, affixPattern.substring(pos, i), localized);
        }
        char c = affixPattern.charAt(++i);
        ++i;
        if (c == QUOTE) {
          buffer.append(c);
          // Fall through and append another QUOTE below
        } else if (c == CURRENCY_SIGN &&
            i < affixPattern.length() &&
            affixPattern.charAt(i) == CURRENCY_SIGN) {
          ++i;
          buffer.append(c);
          // Fall through and append another CURRENCY_SIGN below
        } else if (localized) {
          switch (c) {
            case PATTERN_PERCENT:
              c = symbols.getPercent();
              break;
            case PATTERN_PER_MILLE:
              c = symbols.getPerMill();
              break;
            case PATTERN_MINUS:
              c = symbols.getMinusSign();
              break;
          }
        }
        buffer.append(c);
      }
    }
  }

  /**
   * Append an affix to the given StringBuffer, using quotes if
   * there are special characters.  Single quotes themselves must be
   * escaped in either case.
   */
  private void appendAffix(StringBuffer buffer, String affix, boolean localized) {
    boolean needQuote;
    if (localized) {
      needQuote = affix.indexOf(symbols.getZeroDigit()) >= 0
          || affix.indexOf(symbols.getGroupingSeparator()) >= 0
          || affix.indexOf(symbols.getDecimalSeparator()) >= 0
          || affix.indexOf(symbols.getPercent()) >= 0
          || affix.indexOf(symbols.getPerMill()) >= 0
          || affix.indexOf(symbols.getDigit()) >= 0
          || affix.indexOf(symbols.getPatternSeparator()) >= 0
          || affix.indexOf(symbols.getMinusSign()) >= 0
          || affix.indexOf(CURRENCY_SIGN) >= 0;
    } else {
      needQuote = affix.indexOf(PATTERN_ZERO_DIGIT) >= 0
          || affix.indexOf(PATTERN_GROUPING_SEPARATOR) >= 0
          || affix.indexOf(PATTERN_DECIMAL_SEPARATOR) >= 0
          || affix.indexOf(PATTERN_PERCENT) >= 0
          || affix.indexOf(PATTERN_PER_MILLE) >= 0
          || affix.indexOf(PATTERN_DIGIT) >= 0
          || affix.indexOf(PATTERN_SEPARATOR) >= 0
          || affix.indexOf(PATTERN_MINUS) >= 0
          || affix.indexOf(CURRENCY_SIGN) >= 0;
    }
    if (needQuote) {
      buffer.append('\'');
    }
    if (affix.indexOf('\'') < 0) {
      buffer.append(affix);
    } else {
      for (int j = 0; j < affix.length(); ++j) {
        char c = affix.charAt(j);
        buffer.append(c);
        if (c == '\'') {
          buffer.append(c);
        }
      }
    }
    if (needQuote) {
      buffer.append('\'');
    }
  }

  /**
   * Does the real work of generating a pattern.
   */
  private String toPattern(boolean localized) {
    StringBuffer result = new StringBuffer();
    for (int j = 1; j >= 0; --j) {
      if (j == 1) {
        appendAffix(result, posPrefixPattern, positivePrefix, localized);
      } else {
        appendAffix(result, negPrefixPattern, negativePrefix, localized);
      }
      int i;
      int digitCount = useExponentialNotation
          ? getMaximumIntegerDigits()
          : Math.max(groupingSize, getMinimumIntegerDigits()) + 1;
      for (i = digitCount; i > 0; --i) {
        if (i != digitCount && isGroupingUsed() && groupingSize != 0 &&
            i % groupingSize == 0) {
          result.append(localized ? symbols.getGroupingSeparator() :
              PATTERN_GROUPING_SEPARATOR);
        }
        result.append(i <= getMinimumIntegerDigits()
            ? (localized ? symbols.getZeroDigit() : PATTERN_ZERO_DIGIT)
            : (localized ? symbols.getDigit() : PATTERN_DIGIT));
      }
      if (getMaximumFractionDigits() > 0 || decimalSeparatorAlwaysShown) {
        result.append(localized ? symbols.getDecimalSeparator() :
            PATTERN_DECIMAL_SEPARATOR);
      }
      for (i = 0; i < getMaximumFractionDigits(); ++i) {
        if (i < getMinimumFractionDigits()) {
          result.append(localized ? symbols.getZeroDigit() :
              PATTERN_ZERO_DIGIT);
        } else {
          result.append(localized ? symbols.getDigit() :
              PATTERN_DIGIT);
        }
      }
      if (useExponentialNotation) {
        result.append(localized ? symbols.getExponentSeparator() :
            PATTERN_EXPONENT);
        for (i = 0; i < minExponentDigits; ++i) {
          result.append(localized ? symbols.getZeroDigit() :
              PATTERN_ZERO_DIGIT);
        }
      }
      if (j == 1) {
        appendAffix(result, posSuffixPattern, positiveSuffix, localized);
        if ((negSuffixPattern == posSuffixPattern && // n == p == null
            negativeSuffix.equals(positiveSuffix))
            || (negSuffixPattern != null &&
            negSuffixPattern.equals(posSuffixPattern))) {
          if ((negPrefixPattern != null && posPrefixPattern != null &&
              negPrefixPattern.equals("'-" + posPrefixPattern)) ||
              (negPrefixPattern == posPrefixPattern && // n == p == null
                  negativePrefix.equals(symbols.getMinusSign() + positivePrefix))) {
            break;
          }
        }
        result.append(localized ? symbols.getPatternSeparator() :
            PATTERN_SEPARATOR);
      } else {
        appendAffix(result, negSuffixPattern, negativeSuffix, localized);
      }
    }
    return result.toString();
  }

  /**
   * Apply the given pattern to this Format object.  A pattern is a
   * short-hand specification for the various formatting properties.
   * These properties can also be changed individually through the
   * various setter methods.
   * <p>
   * There is no limit to integer digits set
   * by this routine, since that is the typical end-user desire;
   * use setMaximumInteger if you want to set a real value.
   * For negative numbers, use a second pattern, separated by a semicolon
   * <P>Example <code>"#,#00.0#"</code> &rarr; 1,234.56
   * <P>This means a minimum of 2 integer digits, 1 fraction digit, and
   * a maximum of 2 fraction digits.
   * <p>Example: <code>"#,#00.0#;(#,#00.0#)"</code> for negatives in
   * parentheses.
   * <p>In negative patterns, the minimum and maximum counts are ignored;
   * these are presumed to be set in the positive pattern.
   *
   * @param pattern a new pattern
   * @throws NullPointerException if <code>pattern</code> is null
   * @throws IllegalArgumentException if the given pattern is invalid.
   */
  public void applyPattern(String pattern) {
    applyPattern(pattern, false);
  }

  /**
   * Apply the given pattern to this Format object.  The pattern
   * is assumed to be in a localized notation. A pattern is a
   * short-hand specification for the various formatting properties.
   * These properties can also be changed individually through the
   * various setter methods.
   * <p>
   * There is no limit to integer digits set
   * by this routine, since that is the typical end-user desire;
   * use setMaximumInteger if you want to set a real value.
   * For negative numbers, use a second pattern, separated by a semicolon
   * <P>Example <code>"#,#00.0#"</code> &rarr; 1,234.56
   * <P>This means a minimum of 2 integer digits, 1 fraction digit, and
   * a maximum of 2 fraction digits.
   * <p>Example: <code>"#,#00.0#;(#,#00.0#)"</code> for negatives in
   * parentheses.
   * <p>In negative patterns, the minimum and maximum counts are ignored;
   * these are presumed to be set in the positive pattern.
   *
   * @param pattern a new pattern
   * @throws NullPointerException if <code>pattern</code> is null
   * @throws IllegalArgumentException if the given pattern is invalid.
   */
  public void applyLocalizedPattern(String pattern) {
    applyPattern(pattern, true);
  }

  /**
   * Does the real work of applying a pattern.
   */
  private void applyPattern(String pattern, boolean localized) {
    char zeroDigit = PATTERN_ZERO_DIGIT;
    char groupingSeparator = PATTERN_GROUPING_SEPARATOR;
    char decimalSeparator = PATTERN_DECIMAL_SEPARATOR;
    char percent = PATTERN_PERCENT;
    char perMill = PATTERN_PER_MILLE;
    char digit = PATTERN_DIGIT;
    char separator = PATTERN_SEPARATOR;
    String exponent = PATTERN_EXPONENT;
    char minus = PATTERN_MINUS;
    if (localized) {
      zeroDigit = symbols.getZeroDigit();
      groupingSeparator = symbols.getGroupingSeparator();
      decimalSeparator = symbols.getDecimalSeparator();
      percent = symbols.getPercent();
      perMill = symbols.getPerMill();
      digit = symbols.getDigit();
      separator = symbols.getPatternSeparator();
      exponent = symbols.getExponentSeparator();
      minus = symbols.getMinusSign();
    }
    boolean gotNegative = false;
    decimalSeparatorAlwaysShown = false;
    isCurrencyFormat = false;
    useExponentialNotation = false;

    // Two variables are used to record the subrange of the pattern
    // occupied by phase 1.  This is used during the processing of the
    // second pattern (the one representing negative numbers) to ensure
    // that no deviation exists in phase 1 between the two patterns.
    int phaseOneStart = 0;
    int phaseOneLength = 0;

    int start = 0;
    for (int j = 1; j >= 0 && start < pattern.length(); --j) {
      boolean inQuote = false;
      StringBuffer prefix = new StringBuffer();
      StringBuffer suffix = new StringBuffer();
      int decimalPos = -1;
      int multiplier = 1;
      int digitLeftCount = 0, zeroDigitCount = 0, digitRightCount = 0;
      byte groupingCount = -1;

      // The phase ranges from 0 to 2.  Phase 0 is the prefix.  Phase 1 is
      // the section of the pattern with digits, decimal separator,
      // grouping characters.  Phase 2 is the suffix.  In phases 0 and 2,
      // percent, per mille, and currency symbols are recognized and
      // translated.  The separation of the characters into phases is
      // strictly enforced; if phase 1 characters are to appear in the
      // suffix, for example, they must be quoted.
      int phase = 0;

      // The affix is either the prefix or the suffix.
      StringBuffer affix = prefix;

      for (int pos = start; pos < pattern.length(); ++pos) {
        char ch = pattern.charAt(pos);
        switch (phase) {
          case 0:
          case 2:
            // Process the prefix / suffix characters
            if (inQuote) {
              // A quote within quotes indicates either the closing
              // quote or two quotes, which is a quote literal. That
              // is, we have the second quote in 'do' or 'don''t'.
              if (ch == QUOTE) {
                if ((pos + 1) < pattern.length() &&
                    pattern.charAt(pos + 1) == QUOTE) {
                  ++pos;
                  affix.append("''"); // 'don''t'
                } else {
                  inQuote = false; // 'do'
                }
                continue;
              }
            } else {
              // Process unquoted characters seen in prefix or suffix
              // phase.
              if (ch == digit ||
                  ch == zeroDigit ||
                  ch == groupingSeparator ||
                  ch == decimalSeparator) {
                phase = 1;
                if (j == 1) {
                  phaseOneStart = pos;
                }
                --pos; // Reprocess this character
                continue;
              } else if (ch == CURRENCY_SIGN) {
                // Use lookahead to determine if the currency sign
                // is doubled or not.
                boolean doubled = (pos + 1) < pattern.length() &&
                    pattern.charAt(pos + 1) == CURRENCY_SIGN;
                if (doubled) { // Skip over the doubled character
                  ++pos;
                }
                isCurrencyFormat = true;
                affix.append(doubled ? "'\u00A4\u00A4" : "'\u00A4");
                continue;
              } else if (ch == QUOTE) {
                // A quote outside quotes indicates either the
                // opening quote or two quotes, which is a quote
                // literal. That is, we have the first quote in 'do'
                // or o''clock.
                if (ch == QUOTE) {
                  if ((pos + 1) < pattern.length() &&
                      pattern.charAt(pos + 1) == QUOTE) {
                    ++pos;
                    affix.append("''"); // o''clock
                  } else {
                    inQuote = true; // 'do'
                  }
                  continue;
                }
              } else if (ch == separator) {
                // Don't allow separators before we see digit
                // characters of phase 1, and don't allow separators
                // in the second pattern (j == 0).
                if (phase == 0 || j == 0) {
                  throw new IllegalArgumentException("Unquoted special character '" +
                      ch + "' in pattern \"" + pattern + '"');
                }
                start = pos + 1;
                pos = pattern.length();
                continue;
              }

              // Next handle characters which are appended directly.
              else if (ch == percent) {
                if (multiplier != 1) {
                  throw new IllegalArgumentException(
                      "Too many percent/per mille characters in pattern \"" +
                          pattern + '"');
                }
                multiplier = 100;
                affix.append("'%");
                continue;
              } else if (ch == perMill) {
                if (multiplier != 1) {
                  throw new IllegalArgumentException(
                      "Too many percent/per mille characters in pattern \"" +
                          pattern + '"');
                }
                multiplier = 1000;
                affix.append("'\u2030");
                continue;
              } else if (ch == minus) {
                affix.append("'-");
                continue;
              }
            }
            // Note that if we are within quotes, or if this is an
            // unquoted, non-special character, then we usually fall
            // through to here.
            affix.append(ch);
            break;

          case 1:
            // Phase one must be identical in the two sub-patterns. We
            // enforce this by doing a direct comparison. While
            // processing the first sub-pattern, we just record its
            // length. While processing the second, we compare
            // characters.
            if (j == 1) {
              ++phaseOneLength;
            } else {
              if (--phaseOneLength == 0) {
                phase = 2;
                affix = suffix;
              }
              continue;
            }

            // Process the digits, decimal, and grouping characters. We
            // record five pieces of information. We expect the digits
            // to occur in the pattern ####0000.####, and we record the
            // number of left digits, zero (central) digits, and right
            // digits. The position of the last grouping character is
            // recorded (should be somewhere within the first two blocks
            // of characters), as is the position of the decimal point,
            // if any (should be in the zero digits). If there is no
            // decimal point, then there should be no right digits.
            if (ch == digit) {
              if (zeroDigitCount > 0) {
                ++digitRightCount;
              } else {
                ++digitLeftCount;
              }
              if (groupingCount >= 0 && decimalPos < 0) {
                ++groupingCount;
              }
            } else if (ch == zeroDigit) {
              if (digitRightCount > 0) {
                throw new IllegalArgumentException("Unexpected '0' in pattern \"" +
                    pattern + '"');
              }
              ++zeroDigitCount;
              if (groupingCount >= 0 && decimalPos < 0) {
                ++groupingCount;
              }
            } else if (ch == groupingSeparator) {
              groupingCount = 0;
            } else if (ch == decimalSeparator) {
              if (decimalPos >= 0) {
                throw new IllegalArgumentException("Multiple decimal separators in pattern \"" +
                    pattern + '"');
              }
              decimalPos = digitLeftCount + zeroDigitCount + digitRightCount;
            } else if (pattern.regionMatches(pos, exponent, 0, exponent.length())) {
              if (useExponentialNotation) {
                throw new IllegalArgumentException("Multiple exponential " +
                    "symbols in pattern \"" + pattern + '"');
              }
              useExponentialNotation = true;
              minExponentDigits = 0;

              // Use lookahead to parse out the exponential part
              // of the pattern, then jump into phase 2.
              pos = pos + exponent.length();
              while (pos < pattern.length() &&
                  pattern.charAt(pos) == zeroDigit) {
                ++minExponentDigits;
                ++phaseOneLength;
                ++pos;
              }

              if ((digitLeftCount + zeroDigitCount) < 1 ||
                  minExponentDigits < 1) {
                throw new IllegalArgumentException("Malformed exponential " +
                    "pattern \"" + pattern + '"');
              }

              // Transition to phase 2
              phase = 2;
              affix = suffix;
              --pos;
              continue;
            } else {
              phase = 2;
              affix = suffix;
              --pos;
              --phaseOneLength;
              continue;
            }
            break;
        }
      }

      // Handle patterns with no '0' pattern character. These patterns
      // are legal, but must be interpreted.  "##.###" -> "#0.###".
      // ".###" -> ".0##".
            /* We allow patterns of the form "####" to produce a zeroDigitCount
             * of zero (got that?); although this seems like it might make it
             * possible for format() to produce empty strings, format() checks
             * for this condition and outputs a zero digit in this situation.
             * Having a zeroDigitCount of zero yields a minimum integer digits
             * of zero, which allows proper round-trip patterns.  That is, we
             * don't want "#" to become "#0" when toPattern() is called (even
             * though that's what it really is, semantically).
             */
      if (zeroDigitCount == 0 && digitLeftCount > 0 && decimalPos >= 0) {
        // Handle "###.###" and "###." and ".###"
        int n = decimalPos;
        if (n == 0) { // Handle ".###"
          ++n;
        }
        digitRightCount = digitLeftCount - n;
        digitLeftCount = n - 1;
        zeroDigitCount = 1;
      }

      // Do syntax checking on the digits.
      if ((decimalPos < 0 && digitRightCount > 0) ||
          (decimalPos >= 0 && (decimalPos < digitLeftCount ||
              decimalPos > (digitLeftCount + zeroDigitCount))) ||
          groupingCount == 0 || inQuote) {
        throw new IllegalArgumentException("Malformed pattern \"" +
            pattern + '"');
      }

      if (j == 1) {
        posPrefixPattern = prefix.toString();
        posSuffixPattern = suffix.toString();
        negPrefixPattern = posPrefixPattern;   // assume these for now
        negSuffixPattern = posSuffixPattern;
        int digitTotalCount = digitLeftCount + zeroDigitCount + digitRightCount;
                /* The effectiveDecimalPos is the position the decimal is at or
                 * would be at if there is no decimal. Note that if decimalPos<0,
                 * then digitTotalCount == digitLeftCount + zeroDigitCount.
                 */
        int effectiveDecimalPos = decimalPos >= 0 ?
            decimalPos : digitTotalCount;
        setMinimumIntegerDigits(effectiveDecimalPos - digitLeftCount);
        setMaximumIntegerDigits(useExponentialNotation ?
            digitLeftCount + getMinimumIntegerDigits() :
            MAXIMUM_INTEGER_DIGITS);
        setMaximumFractionDigits(decimalPos >= 0 ?
            (digitTotalCount - decimalPos) : 0);
        setMinimumFractionDigits(decimalPos >= 0 ?
            (digitLeftCount + zeroDigitCount - decimalPos) : 0);
        setGroupingUsed(groupingCount > 0);
        this.groupingSize = (groupingCount > 0) ? groupingCount : 0;
        this.multiplier = multiplier;
        setDecimalSeparatorAlwaysShown(decimalPos == 0 ||
            decimalPos == digitTotalCount);
      } else {
        negPrefixPattern = prefix.toString();
        negSuffixPattern = suffix.toString();
        gotNegative = true;
      }
    }

    if (pattern.length() == 0) {
      posPrefixPattern = posSuffixPattern = "";
      setMinimumIntegerDigits(0);
      setMaximumIntegerDigits(MAXIMUM_INTEGER_DIGITS);
      setMinimumFractionDigits(0);
      setMaximumFractionDigits(MAXIMUM_FRACTION_DIGITS);
    }

    // If there was no negative pattern, or if the negative pattern is
    // identical to the positive pattern, then prepend the minus sign to
    // the positive pattern to form the negative pattern.
    if (!gotNegative ||
        (negPrefixPattern.equals(posPrefixPattern)
            && negSuffixPattern.equals(posSuffixPattern))) {
      negSuffixPattern = posSuffixPattern;
      negPrefixPattern = "'-" + posPrefixPattern;
    }

    expandAffixes();
  }

  /**
   * Sets the maximum number of digits allowed in the integer portion of a
   * number.
   * For formatting numbers other than <code>BigInteger</code> and
   * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
   * 309 is used. Negative input values are replaced with 0.
   *
   * @see NumberFormat#setMaximumIntegerDigits
   */
  @Override
  public void setMaximumIntegerDigits(int newValue) {
    maximumIntegerDigits = Math.min(Math.max(0, newValue), MAXIMUM_INTEGER_DIGITS);
    super.setMaximumIntegerDigits((maximumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
        DOUBLE_INTEGER_DIGITS : maximumIntegerDigits);
    if (minimumIntegerDigits > maximumIntegerDigits) {
      minimumIntegerDigits = maximumIntegerDigits;
      super.setMinimumIntegerDigits((minimumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
          DOUBLE_INTEGER_DIGITS : minimumIntegerDigits);
    }
    fastPathCheckNeeded = true;
  }

  /**
   * Sets the minimum number of digits allowed in the integer portion of a
   * number.
   * For formatting numbers other than <code>BigInteger</code> and
   * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
   * 309 is used. Negative input values are replaced with 0.
   *
   * @see NumberFormat#setMinimumIntegerDigits
   */
  @Override
  public void setMinimumIntegerDigits(int newValue) {
    minimumIntegerDigits = Math.min(Math.max(0, newValue), MAXIMUM_INTEGER_DIGITS);
    super.setMinimumIntegerDigits((minimumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
        DOUBLE_INTEGER_DIGITS : minimumIntegerDigits);
    if (minimumIntegerDigits > maximumIntegerDigits) {
      maximumIntegerDigits = minimumIntegerDigits;
      super.setMaximumIntegerDigits((maximumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
          DOUBLE_INTEGER_DIGITS : maximumIntegerDigits);
    }
    fastPathCheckNeeded = true;
  }

  /**
   * Sets the maximum number of digits allowed in the fraction portion of a
   * number.
   * For formatting numbers other than <code>BigInteger</code> and
   * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
   * 340 is used. Negative input values are replaced with 0.
   *
   * @see NumberFormat#setMaximumFractionDigits
   */
  @Override
  public void setMaximumFractionDigits(int newValue) {
    maximumFractionDigits = Math.min(Math.max(0, newValue), MAXIMUM_FRACTION_DIGITS);
    super.setMaximumFractionDigits((maximumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
        DOUBLE_FRACTION_DIGITS : maximumFractionDigits);
    if (minimumFractionDigits > maximumFractionDigits) {
      minimumFractionDigits = maximumFractionDigits;
      super.setMinimumFractionDigits((minimumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
          DOUBLE_FRACTION_DIGITS : minimumFractionDigits);
    }
    fastPathCheckNeeded = true;
  }

  /**
   * Sets the minimum number of digits allowed in the fraction portion of a
   * number.
   * For formatting numbers other than <code>BigInteger</code> and
   * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
   * 340 is used. Negative input values are replaced with 0.
   *
   * @see NumberFormat#setMinimumFractionDigits
   */
  @Override
  public void setMinimumFractionDigits(int newValue) {
    minimumFractionDigits = Math.min(Math.max(0, newValue), MAXIMUM_FRACTION_DIGITS);
    super.setMinimumFractionDigits((minimumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
        DOUBLE_FRACTION_DIGITS : minimumFractionDigits);
    if (minimumFractionDigits > maximumFractionDigits) {
      maximumFractionDigits = minimumFractionDigits;
      super.setMaximumFractionDigits((maximumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
          DOUBLE_FRACTION_DIGITS : maximumFractionDigits);
    }
    fastPathCheckNeeded = true;
  }

  /**
   * Gets the maximum number of digits allowed in the integer portion of a
   * number.
   * For formatting numbers other than <code>BigInteger</code> and
   * <code>BigDecimal</code> objects, the lower of the return value and
   * 309 is used.
   *
   * @see #setMaximumIntegerDigits
   */
  @Override
  public int getMaximumIntegerDigits() {
    return maximumIntegerDigits;
  }

  /**
   * Gets the minimum number of digits allowed in the integer portion of a
   * number.
   * For formatting numbers other than <code>BigInteger</code> and
   * <code>BigDecimal</code> objects, the lower of the return value and
   * 309 is used.
   *
   * @see #setMinimumIntegerDigits
   */
  @Override
  public int getMinimumIntegerDigits() {
    return minimumIntegerDigits;
  }

  /**
   * Gets the maximum number of digits allowed in the fraction portion of a
   * number.
   * For formatting numbers other than <code>BigInteger</code> and
   * <code>BigDecimal</code> objects, the lower of the return value and
   * 340 is used.
   *
   * @see #setMaximumFractionDigits
   */
  @Override
  public int getMaximumFractionDigits() {
    return maximumFractionDigits;
  }

  /**
   * Gets the minimum number of digits allowed in the fraction portion of a
   * number.
   * For formatting numbers other than <code>BigInteger</code> and
   * <code>BigDecimal</code> objects, the lower of the return value and
   * 340 is used.
   *
   * @see #setMinimumFractionDigits
   */
  @Override
  public int getMinimumFractionDigits() {
    return minimumFractionDigits;
  }

  /**
   * Gets the currency used by this decimal format when formatting
   * currency values.
   * The currency is obtained by calling
   * {@link DecimalFormatSymbols#getCurrency DecimalFormatSymbols.getCurrency}
   * on this number format's symbols.
   *
   * @return the currency used by this decimal format, or <code>null</code>
   * @since 1.4
   */
  @Override
  public Currency getCurrency() {
    return symbols.getCurrency();
  }

  /**
   * Sets the currency used by this number format when formatting
   * currency values. This does not update the minimum or maximum
   * number of fraction digits used by the number format.
   * The currency is set by calling
   * {@link DecimalFormatSymbols#setCurrency DecimalFormatSymbols.setCurrency}
   * on this number format's symbols.
   *
   * @param currency the new currency to be used by this decimal format
   * @throws NullPointerException if <code>currency</code> is null
   * @since 1.4
   */
  @Override
  public void setCurrency(Currency currency) {
    if (currency != symbols.getCurrency()) {
      symbols.setCurrency(currency);
      if (isCurrencyFormat) {
        expandAffixes();
      }
    }
    fastPathCheckNeeded = true;
  }

  /**
   * Gets the {@link java.math.RoundingMode} used in this DecimalFormat.
   *
   * @return The <code>RoundingMode</code> used for this DecimalFormat.
   * @see #setRoundingMode(RoundingMode)
   * @since 1.6
   */
  @Override
  public RoundingMode getRoundingMode() {
    return roundingMode;
  }

  /**
   * Sets the {@link java.math.RoundingMode} used in this DecimalFormat.
   *
   * @param roundingMode The <code>RoundingMode</code> to be used
   * @throws NullPointerException if <code>roundingMode</code> is null.
   * @see #getRoundingMode()
   * @since 1.6
   */
  @Override
  public void setRoundingMode(RoundingMode roundingMode) {
    if (roundingMode == null) {
      throw new NullPointerException();
    }

    this.roundingMode = roundingMode;
    digitList.setRoundingMode(roundingMode);
    fastPathCheckNeeded = true;
  }

  /**
   * Reads the default serializable fields from the stream and performs
   * validations and adjustments for older serialized versions. The
   * validations and adjustments are:
   * <ol>
   * <li>
   * Verify that the superclass's digit count fields correctly reflect
   * the limits imposed on formatting numbers other than
   * <code>BigInteger</code> and <code>BigDecimal</code> objects. These
   * limits are stored in the superclass for serialization compatibility
   * with older versions, while the limits for <code>BigInteger</code> and
   * <code>BigDecimal</code> objects are kept in this class.
   * If, in the superclass, the minimum or maximum integer digit count is
   * larger than <code>DOUBLE_INTEGER_DIGITS</code> or if the minimum or
   * maximum fraction digit count is larger than
   * <code>DOUBLE_FRACTION_DIGITS</code>, then the stream data is invalid
   * and this method throws an <code>InvalidObjectException</code>.
   * <li>
   * If <code>serialVersionOnStream</code> is less than 4, initialize
   * <code>roundingMode</code> to {@link java.math.RoundingMode#HALF_EVEN
   * RoundingMode.HALF_EVEN}.  This field is new with version 4.
   * <li>
   * If <code>serialVersionOnStream</code> is less than 3, then call
   * the setters for the minimum and maximum integer and fraction digits with
   * the values of the corresponding superclass getters to initialize the
   * fields in this class. The fields in this class are new with version 3.
   * <li>
   * If <code>serialVersionOnStream</code> is less than 1, indicating that
   * the stream was written by JDK 1.1, initialize
   * <code>useExponentialNotation</code>
   * to false, since it was not present in JDK 1.1.
   * <li>
   * Set <code>serialVersionOnStream</code> to the maximum allowed value so
   * that default serialization will work properly if this object is streamed
   * out again.
   * </ol>
   *
   * <p>Stream versions older than 2 will not have the affix pattern variables
   * <code>posPrefixPattern</code> etc.  As a result, they will be initialized
   * to <code>null</code>, which means the affix strings will be taken as
   * literal values.  This is exactly what we want, since that corresponds to
   * the pre-version-2 behavior.
   */
  private void readObject(ObjectInputStream stream)
      throws IOException, ClassNotFoundException {
    stream.defaultReadObject();
    digitList = new DigitList();

    // We force complete fast-path reinitialization when the instance is
    // deserialized. See clone() comment on fastPathCheckNeeded.
    fastPathCheckNeeded = true;
    isFastPath = false;
    fastPathData = null;

    if (serialVersionOnStream < 4) {
      setRoundingMode(RoundingMode.HALF_EVEN);
    } else {
      setRoundingMode(getRoundingMode());
    }

    // We only need to check the maximum counts because NumberFormat
    // .readObject has already ensured that the maximum is greater than the
    // minimum count.
    if (super.getMaximumIntegerDigits() > DOUBLE_INTEGER_DIGITS ||
        super.getMaximumFractionDigits() > DOUBLE_FRACTION_DIGITS) {
      throw new InvalidObjectException("Digit count out of range");
    }
    if (serialVersionOnStream < 3) {
      setMaximumIntegerDigits(super.getMaximumIntegerDigits());
      setMinimumIntegerDigits(super.getMinimumIntegerDigits());
      setMaximumFractionDigits(super.getMaximumFractionDigits());
      setMinimumFractionDigits(super.getMinimumFractionDigits());
    }
    if (serialVersionOnStream < 1) {
      // Didn't have exponential fields
      useExponentialNotation = false;
    }
    serialVersionOnStream = currentSerialVersion;
  }

  //----------------------------------------------------------------------
  // INSTANCE VARIABLES
  //----------------------------------------------------------------------

  private transient DigitList digitList = new DigitList();

  /**
   * The symbol used as a prefix when formatting positive numbers, e.g. "+".
   *
   * @serial
   * @see #getPositivePrefix
   */
  private String positivePrefix = "";

  /**
   * The symbol used as a suffix when formatting positive numbers.
   * This is often an empty string.
   *
   * @serial
   * @see #getPositiveSuffix
   */
  private String positiveSuffix = "";

  /**
   * The symbol used as a prefix when formatting negative numbers, e.g. "-".
   *
   * @serial
   * @see #getNegativePrefix
   */
  private String negativePrefix = "-";

  /**
   * The symbol used as a suffix when formatting negative numbers.
   * This is often an empty string.
   *
   * @serial
   * @see #getNegativeSuffix
   */
  private String negativeSuffix = "";

  /**
   * The prefix pattern for non-negative numbers.  This variable corresponds
   * to <code>positivePrefix</code>.
   *
   * <p>This pattern is expanded by the method <code>expandAffix()</code> to
   * <code>positivePrefix</code> to update the latter to reflect changes in
   * <code>symbols</code>.  If this variable is <code>null</code> then
   * <code>positivePrefix</code> is taken as a literal value that does not
   * change when <code>symbols</code> changes.  This variable is always
   * <code>null</code> for <code>DecimalFormat</code> objects older than
   * stream version 2 restored from stream.
   *
   * @serial
   * @since 1.3
   */
  private String posPrefixPattern;

  /**
   * The suffix pattern for non-negative numbers.  This variable corresponds
   * to <code>positiveSuffix</code>.  This variable is analogous to
   * <code>posPrefixPattern</code>; see that variable for further
   * documentation.
   *
   * @serial
   * @since 1.3
   */
  private String posSuffixPattern;

  /**
   * The prefix pattern for negative numbers.  This variable corresponds
   * to <code>negativePrefix</code>.  This variable is analogous to
   * <code>posPrefixPattern</code>; see that variable for further
   * documentation.
   *
   * @serial
   * @since 1.3
   */
  private String negPrefixPattern;

  /**
   * The suffix pattern for negative numbers.  This variable corresponds
   * to <code>negativeSuffix</code>.  This variable is analogous to
   * <code>posPrefixPattern</code>; see that variable for further
   * documentation.
   *
   * @serial
   * @since 1.3
   */
  private String negSuffixPattern;

  /**
   * The multiplier for use in percent, per mille, etc.
   *
   * @serial
   * @see #getMultiplier
   */
  private int multiplier = 1;

  /**
   * The number of digits between grouping separators in the integer
   * portion of a number.  Must be greater than 0 if
   * <code>NumberFormat.groupingUsed</code> is true.
   *
   * @serial
   * @see #getGroupingSize
   * @see java.text.NumberFormat#isGroupingUsed
   */
  private byte groupingSize = 3;  // invariant, > 0 if useThousands

  /**
   * If true, forces the decimal separator to always appear in a formatted
   * number, even if the fractional part of the number is zero.
   *
   * @serial
   * @see #isDecimalSeparatorAlwaysShown
   */
  private boolean decimalSeparatorAlwaysShown = false;

  /**
   * If true, parse returns BigDecimal wherever possible.
   *
   * @serial
   * @see #isParseBigDecimal
   * @since 1.5
   */
  private boolean parseBigDecimal = false;


  /**
   * True if this object represents a currency format.  This determines
   * whether the monetary decimal separator is used instead of the normal one.
   */
  private transient boolean isCurrencyFormat = false;

  /**
   * The <code>DecimalFormatSymbols</code> object used by this format.
   * It contains the symbols used to format numbers, e.g. the grouping separator,
   * decimal separator, and so on.
   *
   * @serial
   * @see #setDecimalFormatSymbols
   * @see java.text.DecimalFormatSymbols
   */
  private DecimalFormatSymbols symbols = null; // LIU new DecimalFormatSymbols();

  /**
   * True to force the use of exponential (i.e. scientific) notation when formatting
   * numbers.
   *
   * @serial
   * @since 1.2
   */
  private boolean useExponentialNotation;  // Newly persistent in the Java 2 platform v.1.2

  /**
   * FieldPositions describing the positive prefix String. This is
   * lazily created. Use <code>getPositivePrefixFieldPositions</code>
   * when needed.
   */
  private transient FieldPosition[] positivePrefixFieldPositions;

  /**
   * FieldPositions describing the positive suffix String. This is
   * lazily created. Use <code>getPositiveSuffixFieldPositions</code>
   * when needed.
   */
  private transient FieldPosition[] positiveSuffixFieldPositions;

  /**
   * FieldPositions describing the negative prefix String. This is
   * lazily created. Use <code>getNegativePrefixFieldPositions</code>
   * when needed.
   */
  private transient FieldPosition[] negativePrefixFieldPositions;

  /**
   * FieldPositions describing the negative suffix String. This is
   * lazily created. Use <code>getNegativeSuffixFieldPositions</code>
   * when needed.
   */
  private transient FieldPosition[] negativeSuffixFieldPositions;

  /**
   * The minimum number of digits used to display the exponent when a number is
   * formatted in exponential notation.  This field is ignored if
   * <code>useExponentialNotation</code> is not true.
   *
   * @serial
   * @since 1.2
   */
  private byte minExponentDigits;       // Newly persistent in the Java 2 platform v.1.2

  /**
   * The maximum number of digits allowed in the integer portion of a
   * <code>BigInteger</code> or <code>BigDecimal</code> number.
   * <code>maximumIntegerDigits</code> must be greater than or equal to
   * <code>minimumIntegerDigits</code>.
   *
   * @serial
   * @see #getMaximumIntegerDigits
   * @since 1.5
   */
  private int maximumIntegerDigits = super.getMaximumIntegerDigits();

  /**
   * The minimum number of digits allowed in the integer portion of a
   * <code>BigInteger</code> or <code>BigDecimal</code> number.
   * <code>minimumIntegerDigits</code> must be less than or equal to
   * <code>maximumIntegerDigits</code>.
   *
   * @serial
   * @see #getMinimumIntegerDigits
   * @since 1.5
   */
  private int minimumIntegerDigits = super.getMinimumIntegerDigits();

  /**
   * The maximum number of digits allowed in the fractional portion of a
   * <code>BigInteger</code> or <code>BigDecimal</code> number.
   * <code>maximumFractionDigits</code> must be greater than or equal to
   * <code>minimumFractionDigits</code>.
   *
   * @serial
   * @see #getMaximumFractionDigits
   * @since 1.5
   */
  private int maximumFractionDigits = super.getMaximumFractionDigits();

  /**
   * The minimum number of digits allowed in the fractional portion of a
   * <code>BigInteger</code> or <code>BigDecimal</code> number.
   * <code>minimumFractionDigits</code> must be less than or equal to
   * <code>maximumFractionDigits</code>.
   *
   * @serial
   * @see #getMinimumFractionDigits
   * @since 1.5
   */
  private int minimumFractionDigits = super.getMinimumFractionDigits();

  /**
   * The {@link java.math.RoundingMode} used in this DecimalFormat.
   *
   * @serial
   * @since 1.6
   */
  private RoundingMode roundingMode = RoundingMode.HALF_EVEN;

  // ------ DecimalFormat fields for fast-path for double algorithm  ------

  /**
   * Helper inner utility class for storing the data used in the fast-path
   * algorithm. Almost all fields related to fast-path are encapsulated in
   * this class.
   *
   * Any {@code DecimalFormat} instance has a {@code fastPathData}
   * reference field that is null unless both the properties of the instance
   * are such that the instance is in the "fast-path" state, and a format call
   * has been done at least once while in this state.
   *
   * Almost all fields are related to the "fast-path" state only and don't
   * change until one of the instance properties is changed.
   *
   * {@code firstUsedIndex} and {@code lastFreeIndex} are the only
   * two fields that are used and modified while inside a call to
   * {@code fastDoubleFormat}.
   */
  private static class FastPathData {
    // --- Temporary fields used in fast-path, shared by several methods.

    /**
     * The first unused index at the end of the formatted result.
     */
    int lastFreeIndex;

    /**
     * The first used index at the beginning of the formatted result
     */
    int firstUsedIndex;

    // --- State fields related to fast-path status. Changes due to a
    //     property change only. Set by checkAndSetFastPathStatus() only.

    /**
     * Difference between locale zero and default zero representation.
     */
    int zeroDelta;

    /**
     * Locale char for grouping separator.
     */
    char groupingChar;

    /**
     * Fixed index position of last integral digit of formatted result
     */
    int integralLastIndex;

    /**
     * Fixed index position of first fractional digit of formatted result
     */
    int fractionalFirstIndex;

    /**
     * Fractional constants depending on decimal|currency state
     */
    double fractionalScaleFactor;
    int fractionalMaxIntBound;


    /**
     * The char array buffer that will contain the formatted result
     */
    char[] fastPathContainer;

    /**
     * Suffixes recorded as char array for efficiency.
     */
    char[] charsPositivePrefix;
    char[] charsNegativePrefix;
    char[] charsPositiveSuffix;
    char[] charsNegativeSuffix;
    boolean positiveAffixesRequired = true;
    boolean negativeAffixesRequired = true;
  }

  /**
   * The format fast-path status of the instance. Logical state.
   */
  private transient boolean isFastPath = false;

  /**
   * Flag stating need of check and reinit fast-path status on next format call.
   */
  private transient boolean fastPathCheckNeeded = true;

  /**
   * DecimalFormat reference to its FastPathData
   */
  private transient FastPathData fastPathData;

  //----------------------------------------------------------------------

  static final int currentSerialVersion = 4;

  /**
   * The internal serial version which says which version was written.
   * Possible values are:
   * <ul>
   * <li><b>0</b> (default): versions before the Java 2 platform v1.2
   * <li><b>1</b>: version for 1.2, which includes the two new fields
   * <code>useExponentialNotation</code> and
   * <code>minExponentDigits</code>.
   * <li><b>2</b>: version for 1.3 and later, which adds four new fields:
   * <code>posPrefixPattern</code>, <code>posSuffixPattern</code>,
   * <code>negPrefixPattern</code>, and <code>negSuffixPattern</code>.
   * <li><b>3</b>: version for 1.5 and later, which adds five new fields:
   * <code>maximumIntegerDigits</code>,
   * <code>minimumIntegerDigits</code>,
   * <code>maximumFractionDigits</code>,
   * <code>minimumFractionDigits</code>, and
   * <code>parseBigDecimal</code>.
   * <li><b>4</b>: version for 1.6 and later, which adds one new field:
   * <code>roundingMode</code>.
   * </ul>
   *
   * @serial
   * @since 1.2
   */
  private int serialVersionOnStream = currentSerialVersion;

  //----------------------------------------------------------------------
  // CONSTANTS
  //----------------------------------------------------------------------

  // ------ Fast-Path for double Constants ------

  /**
   * Maximum valid integer value for applying fast-path algorithm
   */
  private static final double MAX_INT_AS_DOUBLE = (double) Integer.MAX_VALUE;

  /**
   * The digit arrays used in the fast-path methods for collecting digits.
   * Using 3 constants arrays of chars ensures a very fast collection of digits
   */
  private static class DigitArrays {

    static final char[] DigitOnes1000 = new char[1000];
    static final char[] DigitTens1000 = new char[1000];
    static final char[] DigitHundreds1000 = new char[1000];

    // initialize on demand holder class idiom for arrays of digits
    static {
      int tenIndex = 0;
      int hundredIndex = 0;
      char digitOne = '0';
      char digitTen = '0';
      char digitHundred = '0';
      for (int i = 0; i < 1000; i++) {

        DigitOnes1000[i] = digitOne;
        if (digitOne == '9') {
          digitOne = '0';
        } else {
          digitOne++;
        }

        DigitTens1000[i] = digitTen;
        if (i == (tenIndex + 9)) {
          tenIndex += 10;
          if (digitTen == '9') {
            digitTen = '0';
          } else {
            digitTen++;
          }
        }

        DigitHundreds1000[i] = digitHundred;
        if (i == (hundredIndex + 99)) {
          digitHundred++;
          hundredIndex += 100;
        }
      }
    }
  }
  // ------ Fast-Path for double Constants end ------

  // Constants for characters used in programmatic (unlocalized) patterns.
  private static final char PATTERN_ZERO_DIGIT = '0';
  private static final char PATTERN_GROUPING_SEPARATOR = ',';
  private static final char PATTERN_DECIMAL_SEPARATOR = '.';
  private static final char PATTERN_PER_MILLE = '\u2030';
  private static final char PATTERN_PERCENT = '%';
  private static final char PATTERN_DIGIT = '#';
  private static final char PATTERN_SEPARATOR = ';';
  private static final String PATTERN_EXPONENT = "E";
  private static final char PATTERN_MINUS = '-';

  /**
   * The CURRENCY_SIGN is the standard Unicode symbol for currency.  It
   * is used in patterns and substituted with either the currency symbol,
   * or if it is doubled, with the international currency symbol.  If the
   * CURRENCY_SIGN is seen in a pattern, then the decimal separator is
   * replaced with the monetary decimal separator.
   *
   * The CURRENCY_SIGN is not localized.
   */
  private static final char CURRENCY_SIGN = '\u00A4';

  private static final char QUOTE = '\'';

  private static FieldPosition[] EmptyFieldPositionArray = new FieldPosition[0];

  // Upper limit on integer and fraction digits for a Java double
  static final int DOUBLE_INTEGER_DIGITS = 309;
  static final int DOUBLE_FRACTION_DIGITS = 340;

  // Upper limit on integer and fraction digits for BigDecimal and BigInteger
  static final int MAXIMUM_INTEGER_DIGITS = Integer.MAX_VALUE;
  static final int MAXIMUM_FRACTION_DIGITS = Integer.MAX_VALUE;

  // Proclaim JDK 1.1 serial compatibility.
  static final long serialVersionUID = 864413376551465018L;
}
